General: Update $_old_files list, take 2.

This adds one more file to the `$_old_files` list that should be included.

Props barry, johnbillion, jorbin, desrosj.
See #65325.

git-svn-id: https://develop.svn.wordpress.org/trunk@62779 602fd350-edb4-49c9-b593-d223f7449a82

Author: desrosj

src/wp-admin/includes/update-core.php

@@ -899,6 +899,7 @@
 	'wp-includes/js/dist/vendor/react-jsx-runtime.min.js.LICENSE.txt',
 	// 7.0.2
 	'wp-includes/collaboration',
+	'wp-includes/collaboration.php',
 	'wp-includes/js/dist/sync.js'.
 	'wp-includes/js/dist/sync.min.js',
 );