refactor: apply code quality level 54 for Rector

Author: samsonasik

rector.php

@@ -202,4 +202,4 @@
         // keep '\\' prefix string on string '\Foo\Bar'
         StringClassNameToClassConstantRector::SHOULD_KEEP_PRE_SLASH => true,
     ])
-    ->withCodeQualityLevel(53);
+    ->withCodeQualityLevel(54);

system/Filters/PageCache.php

@@ -45,14 +45,7 @@ public function before(RequestInterface $request, $arguments = null)
         assert($request instanceof CLIRequest || $request instanceof IncomingRequest);
 
         $response = service('response');
-
-        $cachedResponse = $this->pageCache->get($request, $response);
-
-        if ($cachedResponse instanceof ResponseInterface) {
-            return $cachedResponse;
-        }
-
-        return null;
+        return $this->pageCache->get($request, $response);
     }
 
     /**