test: Disable pylint warning

It is getting confused through Pydantic, but I've not been able to locate the class to whitelist...

src/qibolab/platform/platform.py

@@ -204,6 +204,7 @@ def channels_map(self) -> dict[str, QubitId]:
 
     def config(self, name: str) -> Config:
         """Returns configuration of given component."""
+        # pylint: disable=unsubscriptable-object
         return self.parameters.configs[name]
 
     def connect(self):