Remove IE support from Twenty Twenty-One

[sabernhardt]

• Removes polyfill scripts, but continues to register their handles.
• Removes IE-specific styles from the main stylesheet.
• Removes the separate IE stylesheets from the build process and from enqueuing functions.
• Removes or replaces contents of the unused files.
• Removes the is-IE class.

Props: iflairwebtechnologies

Trac 64590

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Props sabernhardt.

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[github-actions]

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[westonruter]

So good to remove all this!

[Copilot]

Pull request overview

This PR removes Internet Explorer support from the Twenty Twenty-One WordPress theme. IE11 reached end-of-life in 2022, making this cleanup appropriate for WordPress core themes.

Changes:

• Removed IE-specific stylesheets and SASS imports from build process
• Deprecated IE class detection function and removed its action hook
• Registered empty polyfill script handles for backward compatibility
• Removed polyfill dependencies from navigation and embed scripts

Reviewed changes

Copilot reviewed 8 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
functions.php	Removed IE stylesheet logic, registered empty polyfill handles, removed polyfill dependencies, deprecated twentytwentyone_add_ie_class() function and removed its action hook
package.json	Removed build:ie and build:ie-editor npm scripts
style.css	Removed 58 lines of IE-specific CSS targeting .is-IE class
style-rtl.css	Removed 58 lines of IE-specific RTL CSS
style.css.map	Updated source map to reflect removed IE utilities
assets/sass/style.scss	Removed import of 07-utilities/ie
assets/sass/07-utilities/ie.scss	Replaced IE styles with comment indicating removal
assets/js/polyfills.js	Replaced polyfills with comment indicating removal
assets/css/ie.css.map	Replaced with empty map
assets/css/ie-editor.css	Replaced with comment indicating removal

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[mukeshpanchal27]

Why the function is still present as the action get removed?

Got it. Leave this

[mukeshpanchal27]

Shell we remove this file?

[sabernhardt]

I prefer not to remove any files, though removing an unused .scss file theoretically should be safe.