clean up - no behavior changes

mu-plugins/blocks/global-header-footer/postcss/header/header.pcss

@@ -15,57 +15,34 @@ html {
  * @link https://github.com/WordPress/wporg-mu-plugins/issues/371.
  */
 html.has-modal-open {
-	/* Override https://github.com/WordPress/gutenberg/pull/49369/ on other non-mobile breakpoints to avoid gap on right side of search modal. */
+	/*
+	 * Hotfix for https://github.com/WordPress/gutenberg/pull/49369/. Otherwise the styles below will break when
+	 * we update. Remove this after we install the update
+	 */
+	position: fixed;
+
+	/*
+	 * Override https://github.com/WordPress/gutenberg/pull/49369/. On desktop views it causes a gap to the right
+	 * of the search modal when it's open.
+	 */
 	position: static;
 
 	@media (--mobile-only) {
-		/*position: fixed;*/ /* hotfix for https://github.com/WordPress/gutenberg/pull/49369/. remove when in stable release. */
-		/* if leave ^ enabled, then there's a gap at the bottom of the page where <main> shows through
-		if disable, then safari scroll a little, but it's not visible above the fold
-		 */
-
 		height: 100lvh;
-
 		overflow: hidden;
-		/* todo
-		     maybe set bg color grey to override
-		     try dvh height
-		     try setting height less than 100vh
-
-		     add fixed to header in case that helps
-		    */
-
-		& body{
-			/*
-			none necessary
-			position: fixed;
-			height: 100vh;
-			overflow: hidden;*/
-
-			background: var(--wp--preset--color--charcoal-1);
-		}
 
 		& body:not(.admin-bar) {
 			background: var(--wp--preset--color--charcoal-5);
 		}
 
-
 		& .wp-site-blocks {
-			/* all of this necessary */
 			position: fixed;
 			height: 100vh;
 			overflow: hidden;
 		}
 
 		& .wp-block-navigation__responsive-container {
-			/* need to disable overflow vis from search.pcss? */
-
 			height: 100vh;
-
-			/*
-			these not necessary
-			position: fixed;
-			overflow: hidden;*/
 		}
 
 		& #wpadminbar {