Media & Text: set the default width to none

[carolinan]

What?

WIP, testing fixtures/deprecation

Changes the default align of the Media & Text block from wide to none.
Fixes #20941

Why?

Users and developers have reported that the wide alignment is unexpected and that they would prefer it to be set to none by default (see the discussions in the issue)

How?

Updates the default value of the align block attribute in block.json

Testing Instructions

1. Place a Media & text block in the Site Editor or block editor.
2. Confirm that the width is the default content width, not wide.

[github-actions]

Flaky tests detected in 08d0964.
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/3873065815
📝 Reported issues:

• [Flaky Test] passes the search value in the main inserter when clicking Browse all #45332 in specs/editor/various/inserting-blocks.test.js
• [Flaky Test] should move the blocks down #39691 in specs/editor/various/block-editor-keyboard-shortcuts.test.js

[aaronrobertshaw]

@carolinan I had intended that we merge #48404 into this PR given you got the ball rolling but since I wasn't thinking when I pinged others for review on #48404, it might be cleanest to close this one.

If it's an issue, we can re-juggle things but I'll close this one for now.