Tests: Revert removing empty directory in `WP_UnitTestCase_Base::rmdi…

…r()` for now.

This appears to need more investigation. Instead, delete the `test-plugin` and `link-manager` directories in REST API plugins controller tests, for which this change was initially intended.

Follow-up to [54300], [54301], [54303].

See #55652, #56629.
Built from https://develop.svn.wordpress.org/trunk@54304


git-svn-id: http://core.svn.wordpress.org/trunk@53863 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-beta1-54303';
+$wp_version = '6.1-beta1-54304';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.