[Misc] MultiConnector._connectors type (vllm-project#18423)

Signed-off-by: nicklucche <nlucches@redhat.com>
Signed-off-by: Yuqi Zhang <yuqizhang@google.com>

Author: NickLucche

vllm/distributed/kv_transfer/kv_connector/v1/multi_connector.py

@@ -40,7 +40,7 @@ class MultiConnector(KVConnectorBase_V1):
 
     def __init__(self, vllm_config: "VllmConfig", role: KVConnectorRole):
         super().__init__(vllm_config=vllm_config, role=role)
-        self._connectors = []
+        self._connectors: list[KVConnectorBase_V1] = []
         ktcs = vllm_config.kv_transfer_config.kv_connector_extra_config.get(
             "connectors")
         assert ktcs is not None