Automatically sync stable blocks from Gutenberg to wordpress-develop on release

[gziolo]

Replaces #2647.

Trac ticket: https://core.trac.wordpress.org/ticket/56179.

What problem does this PR solve?

Syncing stable blocks from the Gutenberg repository to wordpress-develop is currently a manual process.

The thing is, it can be automated.

That's what this PR does.

How does this PR solve it?

The big idea is to:

1. Read all the block.json files from the @wordpress/block-library directory.
2. Pick the ones without __experimental restrictions – these are the stable blocks.
3. Use that list to generate PHP code that requires appropriate dynamic blocks PHP files.
4. Use that list to generate PHP code that calls remove_action with appropriate arguments in PHP unit tests.
5. Use that list yet again in Webpack config, instead of the hardcoded one.

All of this is possible thanks to WordPress/gutenberg#40655

To make the process smooth, require and remove_action calls were extracted to separate PPH files that can be easily autogenerated and overwritten:

• wp-includes/blocks/require-dynamic-blocks.php
• wp-includes/blocks/require-static-blocks.php
• tests/phpunit/includes/unregister-blocks-hooks.php

How to test?

1. Wait for the Gutenberg 13.2 release on May 11th where Declare blocks as __experimental in block.json to automate syncing Gutenberg packages to WordPress gutenberg#40655 will be included
2. Confirm all the checks are green on this PR
3. Checkout this branch
4. Run npx grunt sync-gutenberg-packages
5. Confirm all the stable blocks are now represented in the PHP files listed above
6. Confirm all the stable blocks were included in the build.
7. Confirm experimental blocks like post-author-name were excluded from both lists

cc @adamziel

[adamziel]

I think we're good – this is great, thank you so much for taking #2647 across the line! With this PR, 90% of the mundane tasks required for the editor merge process are automated!

[gziolo]

I landed most of the changes with https://core.trac.wordpress.org/changeset/53688. The last remaining piece is the changes to the weback config that requires updating core blocks first.

[azaozz]

Any particular reason the auto-generated PHP files are committed to trunk? Think it was decided to not do that again after the problems with script-loader-packages.php.

Also, these files are supposed to be overwritten every time WP is build, right? So why commit the potentially old versions of them :)

[gziolo]

With https://core.trac.wordpress.org/changeset/54308 all changes are now included in WordPress core.