Allow PHP-Only Block Registration

[t-hamano]

Trac ticket: https://core.trac.wordpress.org/ticket/64639

Use of AI Tools

I am using the Cursor editor and the AI ​​model is auto-selected. I have reviewed all the code myself.

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[github-actions]

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[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.

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Props wildworks, westonruter, ramonopoly, mcsf, oandregal.

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[t-hamano]

The initial approach was to collect the blocks that should be registered and expose them as editor settings in the get_block_editor_settings() function. Now, based on this feedback, I output them as JS inline variables via a new action hook.

[westonruter]

LGTM

[t-hamano]

@oandregal, Based on your suggestion, I've added server-side type checking in 658b7af. I'd be happy to see if this is what you wanted.

[oandregal]

@t-hamano thank you, that's great :) Code changes look good.

[t-hamano]

@oandregal Thanks for the review! After committing this PR to core, I would like to backport similar changes to Gutenberg.

[mcsf]

LGTM too!

[github-actions]

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

SVN changeset: 61661
GitHub commit: 8f6d312

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