PHP 8.3 | PSR12/AnonClassDeclaration: add tests with readonly anonymous classes

The underlying `PSR2.Classes.ClassDeclaration` sniff, which does the actual checking of the space between a potential modifier keyword and the `class` keyword, already handles this correctly (after squizlabs/PHP_CodeSniffer 3826 and 307).

Note: tests were only added to the PSR12 sniffs as that sniffs registers the `T_ANON_CLASS` token.
The `PEAR.Classes.ClassDeclaration` sniff and the `PSR2` and `Squiz` versions, which both extend the `PEAR` class, don't need tests as none of those listen for the `T_ANON_CLASS` token.

Author: jrfnl

src/Standards/PSR12/Tests/Classes/AnonClassDeclarationUnitTest.inc

@@ -88,3 +88,9 @@ $instance = new class() extends SomeClass implements
     SomeInterface{
     public function __construct() {}
 };
+
+// PHP 8.3 readonly anonymous classes.
+$anon = new readonly class {};
+$anon = new readonly    class {};
+$anon = new readonly
+        class {};

src/Standards/PSR12/Tests/Classes/AnonClassDeclarationUnitTest.inc.fixed

@@ -91,3 +91,8 @@ $instance = new class () extends SomeClass implements
 {
     public function __construct() {}
 };
+
+// PHP 8.3 readonly anonymous classes.
+$anon = new readonly class {};
+$anon = new readonly class {};
+$anon = new readonly class {};

src/Standards/PSR12/Tests/Classes/AnonClassDeclarationUnitTest.php

@@ -55,6 +55,8 @@ public function getErrorList()
             75 => 1,
             87 => 1,
             88 => 1,
+            94 => 1,
+            96 => 1,
         ];
 
     }//end getErrorList()