Fix legacy class palceholder definitions for static analysis

Author: ausi

Debug/FileLinkFormatter.php

@@ -25,7 +25,7 @@ class_alias(ErrorHandlerFileLinkFormatter::class, FileLinkFormatter::class);
     /**
      * @deprecated since Symfony 6.4, use FileLinkFormatter from the ErrorHandler component instead
      */
-    class FileLinkFormatter
+    class FileLinkFormatter extends ErrorHandlerFileLinkFormatter
     {
     }
 }

UriSigner.php

@@ -21,7 +21,7 @@ class_exists(HttpFoundationUriSigner::class);
     /**
      * @deprecated since Symfony 6.4, to be removed in 7.0, use {@link HttpFoundationUriSigner} instead
      */
-    class UriSigner
+    class UriSigner extends HttpFoundationUriSigner
     {
     }
 }