Remove all unnecessary stuff from WordPress <head> tag

## wp-head-clean.php
<?php

/**
 * Alter dns-prefetch links in <head>
 */
add_filter('wp_resource_hints', function (array $urls, string $relation): array {
    // If the relation is different than dns-prefetch, leave the URLs intact
    if ($relation !== 'dns-prefetch') {
        return $urls;
    }

    // Remove s.w.org entry
    $urls = array_filter($urls, function (string $url): bool {
        return strpos($url, 's.w.org') === false;
    });

    // List of domains to prefetch:
    $dnsPrefetchUrls = [];
    return array_merge($urls, $dnsPrefetchUrls);
}, 10, 2);

/**
 * Disable RSS feeds by redirecting their URLs to homepage
 */
foreach (['do_feed_rss2', 'do_feed_rss2_comments'] as $feedAction) {
    add_action($feedAction, function (): void {
        // Redirect permanently to homepage
        wp_redirect(home_url(), 301);
        exit;
    }, 1);
}

/**
 * Remove the feed links from <head>
 */
remove_action('wp_head', 'feed_links', 2);

/**
 * Remove emoji script and styles from <head>
 */
remove_action('wp_head', 'print_emoji_detection_script', 7);
remove_action('wp_print_styles', 'print_emoji_styles');

/**
 * Disable REST-API for all users except of admin
 */
add_filter('rest_authentication_errors', function ($access) {
    if (!current_user_can('administrator')) {
        return new WP_Error('rest_cannot_access', 'Only authenticated users can access the REST API.', ['status' => rest_authorization_required_code()]);
    }
    return $access;
});

/**
 * Remove REST-AI link from <head>
 */
remove_action('wp_head', 'rest_output_link_wp_head');

/**
 * Disable XML-RPC
 */
add_filter('xmlrpc_enabled', function (): bool {
    return false;
});

/**
 * Remove XML-RPC link from <head>
 */
remove_action('wp_head', 'rsd_link');

/**
 * Remove Windows Live Writer manifest from <head>
 */
remove_action('wp_head', 'wlwmanifest_link');

/**
 * Remove info about WordPress version from <head>
 */
remove_action('wp_head', 'wp_generator');

/**
 * Remove Gutenberg default styles
 */
add_action('wp_print_styles', function (): void {
    wp_dequeue_style('wp-block-library');
    wp_dequeue_style('wp-block-library-theme');
});

/**
 * Remove unnecessary attributes from style tags
 */
add_filter('style_loader_tag', function (string $tag, string $handle): string {
    // Remove ID attribute
    $tag = str_replace("id='${handle}-css'", '', $tag);

    // Remove type attribute
    $tag = str_replace(" type='text/css'", '', $tag);

    // Change ' to " in attributes:
    $tag = str_replace('\'', '"', $tag);

    // Remove trailing slash
    $tag = str_replace(' />', '>', $tag);

    // Remove double spaces
    return str_replace('  ', '', $tag);
}, 10, 2);