Media: Fix Media Library "Upload files" tab focus outline.

Adds a z-index to `.media-menu .media-menu-item:focus` to fix the "Upload files" tab's outline on the side next to the other tab.

Follow-up to [57553], [46363].

Props wildworks, antpb, huzaifaalmesbah, krupajnanda, nhrrob, oglekler, rajinsharwar, sabernhardt.
Fixes #60632.
Built from https://develop.svn.wordpress.org/trunk@58917


git-svn-id: http://core.svn.wordpress.org/trunk@58313 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/css/media-views-rtl.css

@@ -710,6 +710,7 @@
 	color: #043959;
 	/* Only visible in Windows High Contrast mode */
 	outline: 2px solid transparent;
+	z-index: 1;
 }
 
 .media-router .active,

wp-includes/css/media-views.css

@@ -709,6 +709,7 @@
 	color: #043959;
 	/* Only visible in Windows High Contrast mode */
 	outline: 2px solid transparent;
+	z-index: 1;
 }
 
 .media-router .active,

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.7-alpha-58915';
+$wp_version = '6.7-alpha-58917';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.