feat: add php8.4 images

matrix.php

@@ -20,7 +20,7 @@ function get_digest_of_image(string $imageName, string $tag): string {
     return $digest;
 }
 
-$supportedVersions = ['8.1', '8.2', '8.3'];
+$supportedVersions = ['8.1', '8.2', '8.3', '8.4'];
 $disallowedVersions = ['8.2.20', '8.3.8'];
 $rcVersions = [];