This version of the asset manager is compatible with PHP 8 see original version here (https://gist.github.com/jasonhancock/5073938). The ternary operations have been patched to work with PHP 8

VersionAssetManager.php

<?php

/**
 * CAssetManager class file.
 *
 * @author Jason Hancock <jsnbyh@gmail.com>
 * @copyright Copyright &copy; 2013 Jason Hancock
 * @license http://www.yiiframework.com/license/
 */

/**
 * The goal of the VersionAssetManager is to publish all assets under a version
 * numbered url. This assumes you're incrementing the version number every time
 * you release. For development, we want to emulate the CAssetManager and force
 * the asset publishes and use CRC hashes (like normal), however instead of using
 * the directory's mtime, we're using the current unix time. This means that every
 * pageview when in development mode is copying over all of the assets, so it's
 * expensive, but nothing is more frustrating that trying to solve cache busting
 * issues when you're writing code. In production mode, we use the file's path +
 * the current version number for the hash, so files should only get published
 * once.
 */
class VersionAssetManager extends CAssetManager
{
    private $_basePath;
    private $_baseUrl;
    private $_published = [];
    protected $_time;


    public function publish($path, $hashByName = false, $level = -1, $forceCopy = false)
    {
        if (isset($this->_published[$path])) {
            return $this->_published[$path];
        }
        if (($src = realpath($path)) !== false) {
            if (is_file($src)) {
                $dir = $this->hash($hashByName
                    ? basename($src)
                    : (Yii::app()->params['version'] == 'Development'
                        ? dirname($src).$this->getTime()
                        : dirname($src).Yii::app()->params['version'])
                );
                $fileName = basename($src);
                $dstDir = $this->getBasePath().DIRECTORY_SEPARATOR.$dir;
                $dstFile = $dstDir.DIRECTORY_SEPARATOR.$fileName;

                if ($this->linkAssets) {
                    if (!is_file($dstFile)) {
                        if (!is_dir($dstDir)) {
                            mkdir($dstDir);
                            @chmod($dstDir, $this->newDirMode);
                        }
                        symlink($src, $dstFile);
                    }
                } else {
                    if (@filemtime($dstFile) < @filemtime($src)) {
                        if (!is_dir($dstDir)) {
                            mkdir($dstDir);
                            @chmod($dstDir, $this->newDirMode);
                        }
                        copy($src, $dstFile);
                        @chmod($dstFile, $this->newFileMode);
                    }
                }

                return $this->_published[$path] = $this->getBaseUrl()."/$dir/$fileName";
            } else {
                if (is_dir($src)) {

                    $dir = $this->hash($hashByName
                        ? basename($src)
                        : (Yii::app()->params['version'] == 'Development'
                            ? $src.$this->getTime()
                            : $src.Yii::app()->params['version'])
                    );
                    $dstDir = $this->getBasePath().DIRECTORY_SEPARATOR.$dir;

                    if ($this->linkAssets) {
                        if (!is_dir($dstDir)) {
                            symlink($src, $dstDir);
                        }
                    } else {
                        if (!is_dir($dstDir) || $forceCopy) {
                            CFileHelper::copyDirectory($src, $dstDir, [
                                'exclude' => $this->excludeFiles,
                                'level' => $level,
                                'newDirMode' => $this->newDirMode,
                                'newFileMode' => $this->newFileMode,
                            ]);
                        }
                    }

                    return $this->_published[$path] = $this->getBaseUrl().'/'.$dir;
                }
            }
        }
        throw new CException(Yii::t('yii', 'The asset "{asset}" to be published does not exist.',
            ['{asset}' => $path]));
    }

    /**
     * Returns the published path of a file path.
     * This method does not perform any publishing. It merely tells you
     * if the file or directory is published, where it will go.
     *
     * @param string $path directory or file path being published
     * @param boolean $hashByName whether the published directory should be named as the hashed basename.
     * If false, the name will be the hash taken from dirname of the path being published and path mtime.
     * Defaults to false. Set true if the path being published is shared among
     * different extensions.
     *
     * @return string the published file path. False if the file or directory does not exist
     */
    public function getPublishedPath($path, $hashByName = false)
    {
        if (($path = realpath($path)) !== false) {
            $base = $this->getBasePath().DIRECTORY_SEPARATOR;
            if (is_file($path)) {
                return $base.$this->hash($hashByName
                        ? basename($path)
                        : (Yii::app()->params['version'] == 'Development'
                            ? dirname($path).$this->getTime()
                            : dirname($path).Yii::app()->params['version'])
                    ).DIRECTORY_SEPARATOR.basename($path);
            } else {
                return $base.$this->hash($hashByName
                    ? basename($path)
                    : (Yii::app()->params['version'] == 'Development'
                        ? $path.$this->getTime()
                        : $path.Yii::app()->params['version'])
                );
            }
        } else {
            return false;
        }
    }

    /**
     * Returns the URL of a published file path.
     * This method does not perform any publishing. It merely tells you
     * if the file path is published, what the URL will be to access it.
     *
     * @param string $path directory or file path being published
     * @param boolean $hashByName whether the published directory should be named as the hashed basename.
     * If false, the name will be the hash taken from dirname of the path being published and path mtime.
     * Defaults to false. Set true if the path being published is shared among
     * different extensions.
     *
     * @return string the published URL for the file or directory. False if the file or directory does not exist.
     */
    public function getPublishedUrl($path, $hashByName = false)
    {
        if (isset($this->_published[$path])) {
            return $this->_published[$path];
        }
        if (($path = realpath($path)) !== false) {
            if (is_file($path)) {
                return $this->getBaseUrl().'/'.$this->hash($hashByName
                        ? basename($path)
                        : (Yii::app()->params['version'] == 'Development'
                            ? dirname($path).$this->getTime()
                            : dirname($path).Yii::app()->params['version'])
                    ).'/'.basename($path);
            } else {
                return $this->getBaseUrl().'/'.$this->hash($hashByName
                    ? basename($path)
                    : (Yii::app()->params['version'] == 'Development'
                        ? $path.$this->getTime()
                        : $path.Yii::app()->params['version'])
                );
            }
        } else {
            return false;
        }
    }

    /**
     * Protect against publishing multiple assets for a page view spanning multiple
     * seconds.
     */
    protected function getTime()
    {
        if (!isset($this->_time)) {
            $this->_time = time();
        }

        return $this->_time;
    }
}

Thank you so much for this. You saved me a big hassle 🙏