Update changelog

Author: Seldaek

CHANGELOG.md

@@ -1,8 +1,4 @@
-### 3.4.0 (xxxx-xx-xx)
-* Added `csp > request_matcher` option to allow the use of a custom request matcher (`Symfony\Component\HttpFoundation\RequestMatcherInterface`) (#241)
-* Deprecated `X-Xss-Protection` header, use CSP instead (#342)
-* Fixed Symfony 7.1 deprecation warning (#350)
-* Fixed Twig 3.9 compatibility with yielding extensions (#344)
+# This CHANGELOG is here for historical reasons only, for newer changelog entries see github releases
 
 ### 3.3.0 (2024-04-10)
 * Added `ExternalRedirectResponse` (#331)