fix headers in apply_request_changes

Author: Mantisus

src/crawlee/_types.py

@@ -334,7 +334,7 @@ def apply_request_changes(self, target: Request) -> None:
             target.user_data = self.request.user_data
 
         if self.request.headers != target.headers:
-            target.headers = target.headers | self.request.headers
+            target.headers = self.request.headers
 
 
 @docs_group('Functions')