Editor: reduce specificity of block style variation selector.

Removes duplicate classname from the block style variation selector generated in `WP_Theme_JSON`’s `get_blocks_metadata` function.

Props flixos90, joemcgill, mukesh27, isabel_brison.
Fixes #60312.


git-svn-id: https://develop.svn.wordpress.org/trunk@57490 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-theme-json.php

@@ -947,8 +947,7 @@ protected static function get_blocks_metadata() {
 			if ( ! empty( $block_type->styles ) ) {
 				$style_selectors = array();
 				foreach ( $block_type->styles as $style ) {
-					// The style variation classname is duplicated in the selector to ensure that it overrides core block styles.
-					$style_selectors[ $style['name'] ] = static::append_to_selector( '.is-style-' . $style['name'] . '.is-style-' . $style['name'], static::$blocks_metadata[ $block_name ]['selector'] );
+					$style_selectors[ $style['name'] ] = static::append_to_selector( '.is-style-' . $style['name'], static::$blocks_metadata[ $block_name ]['selector'] );
 				}
 				static::$blocks_metadata[ $block_name ]['styleVariations'] = $style_selectors;
 			}