fix(client): Update exception reference in Assets API client documentation

- Corrected the reference to the `GrpcError` class in the docstring of the `get_microgrid_details` method to point to the appropriate module.
- This change improves the accuracy of the documentation and helps users understand the error handling better.

Signed-off-by: eduardiazf <[email protected]>

Author: eduardiazf

src/frequenz/client/assets/_client.py

@@ -75,7 +75,7 @@ async def get_microgrid_details(  # noqa: DOC502 (raises ApiClientError indirect
 
         Raises:
             ApiClientError: If there are any errors communicating with the Assets API,
-                most likely a subclass of [GrpcError][frequenz.client.assets.GrpcError].
+                most likely a subclass of [GrpcError][frequenz.client.base.exception.GrpcError].
         """
         request = assets_pb2.GetMicrogridRequest(microgrid_id=microgrid_id)
         response = await call_stub_method(