Page Editor: Fix Text global styles for block themes in simple sites

[miksansegundo]

Related to #85798 p1715801793910199-slack-C03TY6J1A

Proposed Changes

• Remove normalize_theme_slug from add_default_editor_styles_for_classic_themes

Note

normalize_theme_slug() is not required because get_stylesheet() returns the theme directory correctly prefixed for simple pub/{ theme directory } and atomic { theme directory }.

Why are these changes being made?

• To fix a bug reported in p1715801793910199-slack-C03TY6J1A affecting only the page editor for block themes on simple sites
• The bug overwrites the Text font with the default editor font
• After the fix, the page editor sues the font from the theme for Text elements (paragraphs)

Testing Instructions

• Sandbox a simple site with bedrock theme
• Patch this diff with install-plugin.sh etk fix/default-styles-for-classic-themes-in-simple
• Go to the Site Editor Styles > Typography > Text and set the font family to Pixeloid mono
• Edit a page from https://wordpress.com/pages/{ SITE }, make sure it has some regular paragraphs
• Verify the paragraphs use the font as on the screenshot

Test on Atomic:

• Download the ETK plugin from Teamcity
• Deactivate ETK on your atomic site
• Upload and install the ETK you downloaded

• Edit a page from https://wordpress.com/pages/{ SITE }, make sure it has some regular paragraphs
• Verify the paragraphs use the font as on the screenshot

BEFORE	AFTER

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

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[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[fushar]

Tested on Simple and Atomic sites, and it works as expected 🎉