Tests: Rename the test file and class for wp_get_global_stylesheet() tests.

This matches the name of the function being tested.

Follow-up to [52675-52677].

See #54782.

git-svn-id: https://develop.svn.wordpress.org/trunk@52682 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/theme/wpGetGlobalStylesheet.php

@@ -1,9 +1,11 @@
 <?php
 
 /**
+ * Tests wp_get_global_stylesheet().
+ *
  * @group themes
  */
-class Tests_Theme_GlobalStylesheet extends WP_UnitTestCase {
+class Tests_Theme_wpGetGlobalStylesheet extends WP_UnitTestCase {
 
 	public function set_up() {
 		parent::set_up();