Add missing dynamic properties using RectorPHP

rector.php

<?php

use Rector\CodeQuality\Rector\Class_\CompleteDynamicPropertiesRector;
use Rector\Config\RectorConfig;

return static function (RectorConfig $rectorConfig): void {
    $rectorConfig->rule(CompleteDynamicPropertiesRector::class);

    // Define directories to check
    $directories = [
        __DIR__ . '/app/code',
        __DIR__ . '/extensions'
    ];

    // Filter out directories that do not exist
    $existingDirectories = array_filter($directories, function ($dir) {
        return is_dir($dir);
    });

    // Add existing directories to the configuration
    $rectorConfig->paths($existingDirectories);
};

Additions to also check template files;

    // Define directories to check
    $directories = [
        __DIR__ . '/app/code',
        __DIR__ . '/app/design',
        __DIR__ . '/extensions'
    ];

   // Add phtml
   $rectorConfig->fileExtensions(['php', 'phtml']);

Also add to check for the PHP version you're upgrading to;

   // PHP 8.2 upgrade
   $rectorConfig->sets([Rector\Set\ValueObject\LevelSetList::UP_TO_PHP_82]);