Navigation Block: Remove obsolete Block Hooks filters

[ockham]

What?

Remove a number of Block Hooks related filters from the Navigation block.

Why?

As of WP 6.6, Core takes care of these things (by adding its own filters):

• block_core_navigation_set_ignored_hooked_blocks_metadata was a helper that was only used by block_core_navigation_update_ignore_hooked_blocks_meta.
• block_core_navigation_update_ignore_hooked_blocks_meta was replaced by update_ignored_hooked_blocks_postmeta, which is added as a default filter here.
• block_core_navigation_insert_hooked_blocks_into_rest_response was replaced by insert_hooked_blocks_into_rest_response, which is added as a default filter here.

And per #67117, 6.6 is the minimum required WordPress version for the Gutenberg plugin.

How?

By removing code.

Note

There's a companion PR in wordpress-develop to move these functions into deprecated.php: WordPress/wordpress-develop#7849

Testing Instructions

This should be covered by unit tests (which are run both against the current and previous WP versions).
In addition, you can smoke-test Block Hooks in the Navigation block as described in other related PRs, e.g. #59021.

[github-actions]

Flaky tests detected in 6bc486d.
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/11933328108
📝 Reported issues:

• [Flaky Test] submenu click on the arrow interactions #61884 in /test/e2e/specs/editor/blocks/navigation-frontend-interactivity.spec.js

[ockham]

This might require a counterpart PR in Core that moves the functions we're removing here into src/wp-includes/deprecated.php 🙈

[github-actions]

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Co-authored-by: ockham <bernhard-reiter@git.wordpress.org>
Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>

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