Remove old block editor package sync scripts

[desrosj]

With the recent changes to the build script, the sync-gutenberg-packages and postsync-gutenberg-packages scripts are no longer necessary.

This removes those scripts and the related supporting logic.

Trac ticket: Core-62839

Use of AI Tools

Example disclosure:

AI assistance: None

---

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[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.

Core Committers: Use this line as a base for the props when committing in SVN:

Props desrosj, youknowriad.

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

[youknowriad]

Good cleanup, I think we still have a tool about running e2e tests that is probably broken. It would be cool if we can fix that to run Gutenberg e2e tests with the new setup.

[github-actions]

Test using WordPress Playground

The changes in this pull request can previewed and tested using a WordPress Playground instance.

WordPress Playground is an experimental project that creates a full WordPress instance entirely within the browser.

Some things to be aware of

• All changes will be lost when closing a tab with a Playground instance.
• All changes will be lost when refreshing the page.
• A fresh instance is created each time the link below is clicked.
• Every time this pull request is updated, a new ZIP file containing all changes is created. If changes are not reflected in the Playground instance,
  it's possible that the most recent build failed, or has not completed. Check the list of workflow runs to be sure.

For more details about these limitations and more, check out the Limitations page in the WordPress Playground documentation.

Test this pull request with WordPress Playground.

[github-actions]

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 62062
GitHub commit: 1ed4e1a

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.