refactor: update flex property in document bar title style (#64092)

Co-authored-by: amitraj2203 <amitraj2203@git.wordpress.org>
Co-authored-by: stokesman <presstoke@git.wordpress.org>
Co-authored-by: Rishit30G <rishit30g@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>

packages/editor/src/components/document-bar/style.scss

@@ -34,7 +34,7 @@
 }
 
 .editor-document-bar__title {
-	flex-grow: 1;
+	flex: 1;
 	overflow: hidden;
 	color: $gray-900;
 	gap: $grid-unit-05;