[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

pytest_aiohttp/plugin.py

@@ -160,7 +160,7 @@ async def go(
         elif isinstance(__param, BaseTestServer):
             client = aiohttp_client_cls(__param, **kwargs)
         else:
-            raise ValueError("Unknown argument type: %r" % type(__param))
+            raise ValueError(f"Unknown argument type: {type(__param)!r}")
 
         await client.start_server()
         clients.append(client)