jetpack General: remove deprecated methods.

Proposed changes:

This PR removes deprecated methods and files that were marked as deprecated before Jetpack 10.0 was released, back in August 2021.

Some remain, when they are still in use on WordPress.com Simple.

This PR ends up removing a significant part of the Compat package, since those classes and methods do not appear to be used in active W.org plugins at the moment (as per a search on wpdirectory.net). Only the GP_Locale and GP_Locales classes remain; maybe those should be moved somewhere else at this point, in their own package?

This PR also removes a compatibility layer that was added for the Crowdsignal plugin. That layer does not seem necessary anymore, since: https://github.com/Automattic/crowdsignal-plugin/commit/941fc5758152ebf860a14d1cd0058245e8aed86b

Noting that as part of this change, I also landed D140596-code to ensure tests will continue to work on WordPress.com after this change is merged.

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:

Ensure you can continue to connect the Jetpack plugin to WordPress.com.
Ensure that usage of GP_Locale or GP_Locales in the Jetpack plugin continues to work as expected. Places to test: notifications, Facebook's official sharing button, Instant Search.

Mar 04 '24 16:03 jeherve

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

:white_check_mark: Include a description of your PR changes.
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This comment will be updated as you work on your PR and make changes. If you think that some of those checks are not needed for your PR, please explain why you think so. Thanks for cooperation :robot:

The e2e test report can be found here. Please note that it can take a few minutes after the e2e tests checks are complete for the report to be available.

Once your PR is ready for review, check one last time that all required checks appearing at the bottom of this PR are passing or skipped. Then, add the "[Status] Needs Team Review" label and ask someone from your team review the code. Once reviewed, it can then be merged. If you need an extra review from someone familiar with the codebase, you can update the labels from "[Status] Needs Team Review" to "[Status] Needs Review", and in that case Jetpack Approvers will do a final review of your PR.

Jetpack plugin:

The Jetpack plugin has different release cadences depending on the platform:

WordPress.com Simple releases happen daily.
WoA releases happen weekly.
Releases to self-hosted sites happen monthly. The next release is scheduled for April 2, 2024 (scheduled code freeze on April 1, 2024).

If you have any questions about the release process, please ask in the #jetpack-releases channel on Slack.

Mar 04 '24 16:03 github-actions[bot]

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 rm/deprecated-files-methods branch.

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

bin/jetpack-downloader test jetpack rm/deprecated-files-methods

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

Mar 04 '24 16:03 github-actions[bot]

@fgiannar @darssen Since this is removing some old Sync-related classes, I wanted to rope you in for a review since you may have an opinion on that. Thank you!

Mar 04 '24 17:03 jeherve