Preparation for PHP8.4

[noone-silent]

Currently if we have a signature like this:

    public static function query(<DiInterface> container = null) -> <CriteriaInterface>

The stubs will generate a signature like this:

    /**
     * @param \Phalcon\Di\DiInterface $container
     * @return CriteriaInterface
     */
    public static function query(\Phalcon\Di\DiInterface $container = null): CriteriaInterface

First of, this is wrong, because null is missing as a allowed parameter. Second, it will raise deprecation warnings with PHP8.4. The produced code should be:

    /**
     * @param \Phalcon\Di\DiInterface|null $container
     * @return CriteriaInterface
     */
    public static function query(?\Phalcon\Di\DiInterface $container = null): CriteriaInterface

or

    /**
     * @param \Phalcon\Di\DiInterface|null $container
     * @return CriteriaInterface
     */
    public static function query(\Phalcon\Di\DiInterface | null $container = null): CriteriaInterface

This can already be included, because | null is allowed since PHP8.0.

I know they're only stubs, but event the stubs should be correct. Also probably check the generated C code, maybe the problem exists there too.