Aspect ratio: remove support on the Group block for now

[andrewserong]

What?

Following on from feedback on #56897, let's remove aspect ratio support from the Group block for now.

Why?

Aspect ratio support is a natural fit for the Cover block where folks are actively using min-height controls and the block has a default min height, with everything centred by default. With the Group block, positioning controls aren't exposed by default, and the use case for aspect ratio there is quite nuanced (likely only really works well with particular Row and Stack blocks, and depending on the kind of contents in use)

So, until we have a solid use case for re-enabling it and/or a good way to hide the control until it's really needed, this PR proposes leaving Group block without aspect ratio support for WP 6.5. This will give us a bit more time to consider whether or not it should be included with the Group block further down the track, as it will be much easier to re-add the control than to remove it once it's in a major release.

How?

• Update the Group block's block.json file to remove aspect ratio support

Testing Instructions

• With this PR applied, add a Group block to a post or page — there should be no aspect ratio control available
• Add a Cover block. There should still be an aspect ratio control available

Testing Instructions for Keyboard

Screenshots or screencast

Group block dimensions	Cover block dimensions

[github-actions]

Flaky tests detected in 60fbfd0.
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/7702692781
📝 Reported issues:

• [Flaky Test] directives inside islands should not be hydrated twice #58332 in /test/e2e/specs/interactivity/tovdom-islands.spec.ts

[andrewserong]

Thanks for the quick review, Rob! 🙇

[jasmussen]

Thank you! We can potentially explore re-enabling this in the future depending on how it works in the Cover block. But for now, the Cover with the DNA it shares with Image, means the two are sides of a coin and it's a good fit there.

[cbravobernal]

I just cherry-picked this PR to the release/17.6 branch to get it included in the next release: 7ec2d92