RTC: Enable when WordPress 7.0+ is detected without Gutenberg

[mmtr]

Fixes DOTCOM-16598

Proposed changes

• Enable RTC on sites running WordPress 7.0+ even when the Gutenberg plugin is not installed, since WP 7.0 includes RTC support in core.
• Uses strtok to strip beta/RC suffixes from $wp_version so pre-release versions (e.g. 7.0-beta1, 7.0-RC1) also match.

Related product discussion/links

N/A

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

No.

Testing instructions

• On a site running WordPress 7.0-beta (or RC) without the Gutenberg plugin installed, verify that RTC is enabled (the wp_collaboration_enabled option defaults to on).
• On a site running WordPress 7.0+ with Gutenberg >= 22.7.0, verify RTC still works as before.
• On a site running WordPress < 7.0 without Gutenberg, verify RTC remains disabled.

🤖 Generated with Claude Code

[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 WoA dev 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 (WordPress.com Site Helper), and enable the dotcom-16598-rtc-test-with-wp-70 branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack-mu-wpcom-plugin dotcom-16598-rtc-test-with-wp-70

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

[github-actions]

Thank you for your PR!

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

• ✅ Include a description of your PR changes.
  
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• ✅ Add testing instructions.
  
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• ✅ Add changelog entries to affected projects
  

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[jp-launch-control]

Code Coverage Summary

Coverage changed in 1 file.

File	Coverage	Δ%	Δ Uncovered
projects/packages/jetpack-mu-wpcom/src/features/gutenberg-rtc/gutenberg-rtc.php	23/43 (53.49%)	-1.27%	1 ❤️‍🩹

Full summary · PHP report