Fix block library and global styles stylesheet ordering when a block style variation is active

[talldan]

Fixes #63912

Core backport: WordPress/wordpress-develop#7088
Trac Ticket: https://core.trac.wordpress.org/ticket/61748

What?

Reorders the dependencies for block-style-variations-styles

Why?

The order of the dependencies here was causing different ordering of stylesheets on the page

When a theme is using theme.json presets that match the naming used by core, this can suddenly cause those core styles to override those from the theme.json (the css variables from core take precedence over those generated from the theme.json.

Props to @aaronrobertshaw for spotting the problematic line of code

Testing Instructions

• Alter the Twenty Twenty Four theme.json file to include a font size with the slug normal that is something fairly large, like 2rem
• Make a page with some text using that font size and preview it - note that the text is correctly sized to 2rem
• Add a button with the Outline style on the same page and preview it again

Expected: the text is still 2rem
Before: the text was incorrectly 16px

Screenshots or screencast

Before

Regular button	Outline button

After

Regular button	Outline button

[github-actions]

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Co-authored-by: talldan <talldanwp@git.wordpress.org>
Co-authored-by: andrewserong <andrewserong@git.wordpress.org>
Co-authored-by: ramonjd <ramonopoly@git.wordpress.org>
Co-authored-by: aaronrobertshaw <aaronrobertshaw@git.wordpress.org>
Co-authored-by: eric-michel <ytfeldrawkcab@git.wordpress.org>

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[ramonjd]

Here's what I'm seeing on the frontend. All my elements have the "normal" font size applied, at 3.333rem

Before	After

All looks fine in the editor before and after.

[andrewserong]

Nice simple fix, good work identifying it @aaronrobertshaw, and thanks for the quick PR @talldan!

This is testing nicely for me and follows the order in which these are registered normally in core, too (outside of block style variations) 👍

Before	After

I also quickly smoke tested that custom block style variations are working as expected for me, too (screenshot includes a style variation for paragraph and button blocks):

LGTM! 🚀

[ramonjd]

LGTM

Global styles CSS is now taking precedence over the block library common CSS

Before	After

[aaronrobertshaw]

LGTM as well 👍

✅ Could replicate issue
✅ Applying the fix resolves the problem
✅ Fix works regardless of whether core block assets are loaded separately

[hellofromtonya]

Removed the Needs PHP Backport label as the PHP changes were committed into WordPress Core's trunk and backported to WordPress' Core 6.6 branch for 6.6.2.

[talldan]

I've cherry picked this to the wp/6.6 branch to keep the code in sync - ae218b7.