Docs: Remove @return void from various DocBlocks.

Per the documentation standards, it should not be used outside of the default bundled themes.

Follow-up to [52049], [52051], [53331], [54156], [54214], [55203], [55719].

See #57840.

git-svn-id: https://develop.svn.wordpress.org/trunk@55725 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/style-engine/class-wp-style-engine-processor.php

@@ -126,8 +126,6 @@ class WP_Style_Engine_Processor {
 	 * Combines selectors from the rules store when they have the same styles.
 	 *
 	 * @since 6.1.0
-	 *
-	 * @return void
 	 */
 	private function combine_rules_selectors() {
 		// Build an array of selectors along with the JSON-ified styles to make comparisons easier.