Remove redundant replica_pg reassignment in deployment scheduler

Signed-off-by: Ryan O'Leary <ryanaoleary@google.com>

Author: ryanaoleary

python/ray/serve/_private/deployment_scheduler.py

@@ -665,7 +665,6 @@ def _schedule_replica(
             # - The user provided an accelerator_config that derives its own
             #   bundles from structured fields (e.g. TPUAcceleratorConfig
             #   derives bundles from topology via slice_placement_group).
-            replica_pg = None
             placement_group_strategy = (
                 scheduling_request.placement_group_strategy
                 if scheduling_request.placement_group_strategy