Description

The default aspectRatio set in theme.json doesn't work

Step-by-step reproduction instructions

1. Add the following code to the default settings of the block in theme.json.

"core/post-featured-image": {
	"dimensions": {
		"aspectRatio": "1"
	}
},

2. Go to post or page and place the Featured image block.

3. You will see that the CSS for the default aspect ratio does not work.

Related：#47271

Screenshots, screen recording, code snippet

Environment info

WordPress version: 6.7.2
Twenty Twenty-Five
Gutenberg: version: 20.6.0-rc.1

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure