enh: redis dict for internal models state

Co-Authored-By: cw.a <57549718+acwoo97@users.noreply.github.com>

backend/open_webui/socket/main.py

@@ -118,6 +118,14 @@ if WEBSOCKET_MANAGER == "redis":
     redis_sentinels = get_sentinels_from_env(
         WEBSOCKET_SENTINEL_HOSTS, WEBSOCKET_SENTINEL_PORT
     )
+
+    MODELS = RedisDict(
+        f"{REDIS_KEY_PREFIX}:models",
+        redis_url=WEBSOCKET_REDIS_URL,
+        redis_sentinels=redis_sentinels,
+        redis_cluster=WEBSOCKET_REDIS_CLUSTER,
+    )
+
     SESSION_POOL = RedisDict(
         f"{REDIS_KEY_PREFIX}:session_pool",
         redis_url=WEBSOCKET_REDIS_URL,
@@ -148,6 +156,8 @@ if WEBSOCKET_MANAGER == "redis":
     renew_func = clean_up_lock.renew_lock
     release_func = clean_up_lock.release_lock
 else:
+    MODELS = {}
+
     SESSION_POOL = {}
     USER_POOL = {}
     USAGE_POOL = {}