Ignore the 'twentytwentyfour' test theme dir created by wp-env

[Mamaduka]

What?

This is similar to #53031.

Adds twentytwentyfour theme to the ignored test theme list.

Why?

→ warning: failed to remove test/gutenberg-test-themes/twentytwentyfour/: Permission denied

Testing Instructions

• Run npx wp-env start --update - you should see twentytwentyfour downloaded and installed as per this config.
• Confirm that the above theme folders have been created inside /test/gutenberg-test-themes/ folder (they should be empty).
• Make any change to any file and try to commit it - you should be able to do this without the aforementioned issue on this branch and not on trunk.

[draganescu]

curious this didn't show in git status

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

If you're merging code through a pull request on GitHub, copy and paste the following into the bottom of the merge commit message.

Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>
Co-authored-by: draganescu <andraganescu@git.wordpress.org>

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[draganescu]

🙏🏻

[github-actions]

Flaky tests detected in 33aed3d.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/7915630700
📝 Reported issues:

• [Flaky Test] submenu converts to link automatically #58981 in /test/e2e/specs/editor/blocks/navigation.spec.js

[youknowriad]

@Mamaduka I think you forgot the props bot :P

[Mamaduka]

Props bot, blame @draganescu :D

[draganescu]

I did paste the props bot thing and then enabled automerge.

[youknowriad]

You just lost a prop @draganescu :P just blame yourself