Automated Testing: Disable remote patterns in tests

[Mamaduka]

Description

Adds new "mu-plugin" to disable loading remote patterns loading in tests.

Fixes #33126

How has this been tested?

1. Symlink new "disable-remote-patterns.php" mu-plugin to your local mu-plugins directory.
2. Remote patterns shouldn't be loaded in the editor.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).

[Mamaduka]

Hi, @ntsekouras

Should we go with this solution for #33126?

[jorgefilipecosta]

This solution seems good to me 👍 I guess not relying on an external source makes sense. But I also wonder that if we have a critical issues e.g: crash on remote block patterns our tests will never detect that.

[Mamaduka]

As far as I know, remote patterns are just standard patterns loaded via HTTP and registered on the PHP side. So if something breaks in patterns API, we should notice it based on patterns we ship with the plugin.

If the problem is with the remote pattern itself, I think it should be fixed in the patterns directory.