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


git-svn-id: https://develop.svn.wordpress.org/trunk@40564 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/rewrite.php

@@ -122,8 +122,6 @@ class Tests_Rewrite extends WP_UnitTestCase {
 	 * @group ms-required
 	 */
 	function test_url_to_postid_of_http_site_when_current_site_uses_https() {
-		$this->skipWithoutMultisite();
-
 		$_SERVER['HTTPS'] = 'on';
 
 		$network_home = home_url();
@@ -317,8 +315,6 @@ class Tests_Rewrite extends WP_UnitTestCase {
 	 * @group ms-required
 	 */
 	function test_url_to_postid_ms_home_url_collision() {
-		$this->skipWithoutMultisite();
-
 		$blog_id = self::factory()->blog->create( array( 'path' => '/example' ) );
 		switch_to_blog( $blog_id );