Build/Test Tools: Automatically skip tests in the `ms-required` and `ms-excluded` groups.

This removes the need to manually call `$this->skipWithMultisite()` and `$this->skipWithoutMultisite()` from within the test when the test only runs without Multisite or only runs on Multisite, respectively.

Props jdgrimes for the suggestion.

Fixes #40531

Built from https://develop.svn.wordpress.org/trunk@40564


git-svn-id: http://core.svn.wordpress.org/trunk@40433 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-40563';
+$wp_version = '4.8-alpha-40564';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.