Customize: Use static closures in tests to reduce memory usage.

Follow-up to [60499].

Props mukesh27.
See #63632.


git-svn-id: https://develop.svn.wordpress.org/trunk@60500 602fd350-edb4-49c9-b593-d223f7449a82

Author: westonruter

tests/phpunit/tests/theme/wpTheme.php

@@ -410,7 +410,7 @@ public function test_wp_customize_url_with_existing_query_args() {
 		// Ensure the existing query arg is present in the URL.
 		add_filter(
 			'admin_url',
-			function ( $url ) {
+			static function ( $url ) {
 				return add_query_arg( 'existing_arg', 'value', $url );
 			}
 		);
@@ -430,7 +430,7 @@ public function test_wp_customize_url_with_existing_theme_query_arg() {
 		// Ensure the theme query arg is replaced with the new value.
 		add_filter(
 			'admin_url',
-			function ( $url ) {
+			static function ( $url ) {
 				return add_query_arg( 'theme', 'to-be-replaced', $url );
 			}
 		);
@@ -450,7 +450,7 @@ public function test_wp_customize_url_with_multiple_theme_query_args() {
 		// Ensure the theme query arg is replaced with the new value.
 		add_filter(
 			'admin_url',
-			function ( $url ) {
+			static function ( $url ) {
 				return add_query_arg( array( 'theme' => array( 'to-be-replaced-1', 'to-be-replaced-2' ) ), $url );
 			}
 		);