Fix: Make streams local, not global

Signed-off-by: Mathias L. Baumann <mathias.baumann@frequenz.com>

Author: Marenz

src/frequenz/client/dispatch/_client.py

@@ -55,11 +55,6 @@
 class Client(BaseApiClient[dispatch_pb2_grpc.MicrogridDispatchServiceStub]):
     """Dispatch API client."""
 
-    streams: dict[
-        int, GrpcStreamBroadcaster[StreamMicrogridDispatchesResponse, DispatchEvent]
-    ] = {}
-    """A dictionary of streamers, keyed by microgrid_id."""
-
     def __init__(
         self,
         *,
@@ -91,6 +86,10 @@ def __init__(
             ),
         )
         self._metadata = (("key", key),)
+        self.streams: dict[
+            int, GrpcStreamBroadcaster[StreamMicrogridDispatchesResponse, DispatchEvent]
+        ] = {}
+        """A dictionary of streamers, keyed by microgrid_id."""
 
     @property
     def stub(self) -> dispatch_pb2_grpc.MicrogridDispatchServiceAsyncStub: