MU WPCOM: Stop loading wpcom block editor nux feature

[mmtr]

Fixes the regression that has been escalated in p1723186454644719-slack-C02FMH4G8
Reverts #38674

Proposed changes:

Apparently, the automattic/wpcom-welcome-guide store is not available when the Gutenberg plugin is disabled and that causes a failure to the starter-page-templates feature.

It looks like a regression introduced after moving the wpcom block editor nux feature from ETK to jetpack-mu-wpcom (#38674), so as a temporary solution this PR stops loading the feature from jetpack-mu-wpcom.

Before	After

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

N/A

Does this pull request change what data or activity we track or use?

No

Testing instructions:

• Apply these changes to your WoA dev site
• Disable the Gutenberg plugin
• Go to /wp-admin/post-new.php?post_type=page
• Make sure the "Add a page" modal shows up successfully

[github-actions]

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[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WordPress.com Simple site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin, and enable the fix/pagte-patterns-error branch.

  • For jetpack-mu-wpcom changes, also add define( 'JETPACK_MU_WPCOM_LOAD_VIA_BETA_PLUGIN', true ); to your wp-config.php file.

• To test on Simple, run the following command on your sandbox:

  bin/jetpack-downloader test jetpack-mu-wpcom-plugin fix/pagte-patterns-error
  

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[arthur791004]

We have to comment the following one to enable the feature from ETK

define( 'MU_WPCOM_BLOCK_EDITOR_NUX', true );

[BogdanUngureanu]

Tests well on Simple and AT.