PHP Deprecated: ctype_digit(): Argument of type null will be interpreted as string

[cabrerahector]

From PHP docs:

Warning

As of PHP 8.1.0, passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr() should be made.

This warning is being triggered by this line from Image.php:

if ( ! ctype_digit($quality) ) {
    ...
}

One potential solution would be to cast $quality as string, like so:

if ( ! ctype_digit((string) $quality) ) {
    ...
}