ci: Fix lint errors.

Now that we're using python 3.12 for the `lint` github action, we need
to fix the errors that it is reporting.

esrally/client/asynchronous.py

@@ -77,7 +77,7 @@ async def send(self, conn: "Connection") -> "ClientResponse":
         self.response = self.response_class(
             self.method,
             self.original_url,
-            writer=self._writer,  # type: ignore[arg-type]  # TODO remove this ignore when introducing type hints
+            writer=self._writer,
             continue100=self._continue,
             timer=self._timer,
             request_info=self.request_info,