[Php83] Fix invalid constant use READONLY_CLASS -> READONLY_ANONYMOUS_CLASS on ReadOnlyAnonymousClassRector (#6936)

Author: samsonasik

rules/Php83/Rector/Class_/ReadOnlyAnonymousClassRector.php

@@ -73,6 +73,6 @@ public function refactor(Node $node): ?Node
 
     public function provideMinPhpVersion(): int
     {
-        return PhpVersionFeature::READONLY_CLASS;
+        return PhpVersionFeature::READONLY_ANONYMOUS_CLASS;
     }
 }