NamingConventions/ValidFunctionName: add tests using readonly anonymous classes

This commit adds a few tests using readonly anonymous classes to the `WordPress.NamingConventions.ValidFunctionName` tests. This is just to ensure that the part of the sniff code that checks for `T_ANON_CLASS` tokens works correctly with readonly anonymous class added in PHP 8.3.

The sniff was already handling readonly anonymous classes correctly, and no change to the sniff code is needed.

Author: rodrigoprimo

WordPress/Tests/NamingConventions/ValidFunctionNameUnitTest.1.inc

@@ -222,3 +222,12 @@ enum Suit {
 function lähtöaika() {} // OK.
 function lÄhtÖaika() {} // Bad, but only handled by the sniff if Mbstring is available.
 function lÄhtOaika() {} // Bad, handled via transliteration of non-ASCII chars if Mbstring is not available.
+
+/*
+ * Safeguard that PHP 8.3+ readonly anonymous classes are handled correctly.
+ */
+$anon_class = new readonly class() {
+    public function camelCase() {} // Bad.
+    protected function __something() {} // Bad.
+    private function snake_case() {} // Ok.
+};

WordPress/Tests/NamingConventions/ValidFunctionNameUnitTest.php

@@ -60,6 +60,8 @@ public function getErrorList( $testFile = '' ) {
 					210 => 1,
 					223 => function_exists( 'mb_strtolower' ) ? 1 : 0,
 					224 => 1,
+					230 => 1,
+					231 => 1,
 				);
 
 			default: