Updated to 'phpdocumentor/reflection:~5.3'

[ghost]

CHANGES

• Updated to php:>=8.2.
• Updated to phpdocumentor/reflection:~5.3.
• Removed references to WordPress core.
• Unit tests using 'GitHub Actions'.
• The 'uses' attribute is no longer available for files. Not supported by the new version of phpdocumentor/reflection.

TODO

• Restructure '/tests' directory.
• Add more unit tests.

[johnbillion]

Thank you for your PR @otrocodigo. I'm not sure why I didn't see this sooner.

I'm not sure why the GitHub Actions workflow isn't running, let me look into it.