refactor(redis): build the async auth kwargs instead of mutating them twice

Both async entrypoints edited the kwargs dict in place with the same five
lines. One shared transform returns the swapped copy instead.

Author: mateo-berri

litellm/_redis.py

@@ -594,6 +594,18 @@ def _async_credential_provider(redis_connect_func: object | None) -> CredentialP
     return None
 
 
+def _async_auth_kwargs(redis_kwargs: dict) -> dict:
+    """Swaps a connect func an async path cannot run for the equivalent credential provider,
+    which supersedes any static username or password redis-py would otherwise reject it with."""
+    credential_provider: Final = _async_credential_provider(redis_kwargs.get("redis_connect_func"))
+    if credential_provider is None:
+        return redis_kwargs
+
+    superseded: Final = frozenset({"redis_connect_func", "username", "password"})
+    kept: Final = ((k, v) for k, v in redis_kwargs.items() if k not in superseded)
+    return dict(kept, credential_provider=credential_provider)  # mutable-ok: the branches below mutate these kwargs
+
+
 def get_redis_client(**env_overrides):
     redis_kwargs: Final = _get_redis_client_logic(**env_overrides)
 
@@ -620,12 +632,7 @@ def get_redis_async_client(
     connection_pool: async_redis.BlockingConnectionPool | None = None,
     **env_overrides,
 ) -> async_redis.Redis | async_redis.RedisCluster:
-    redis_kwargs: Final = _get_redis_client_logic(**env_overrides)
-    credential_provider: Final = _async_credential_provider(redis_kwargs.get("redis_connect_func"))
-    if credential_provider is not None:
-        redis_kwargs["credential_provider"] = credential_provider
-        for superseded in ("redis_connect_func", "username", "password"):
-            redis_kwargs.pop(superseded, None)
+    redis_kwargs: Final = _async_auth_kwargs(_get_redis_client_logic(**env_overrides))
 
     if "startup_nodes" in redis_kwargs:
         from redis.cluster import ClusterNode
@@ -688,12 +695,7 @@ def get_redis_async_client(
 def get_redis_connection_pool(
     **env_overrides,
 ) -> async_redis.BlockingConnectionPool | None:
-    redis_kwargs: Final = _get_redis_client_logic(**env_overrides)
-    credential_provider: Final = _async_credential_provider(redis_kwargs.get("redis_connect_func"))
-    if credential_provider is not None:
-        redis_kwargs["credential_provider"] = credential_provider
-        for superseded in ("redis_connect_func", "username", "password"):
-            redis_kwargs.pop(superseded, None)
+    redis_kwargs: Final = _async_auth_kwargs(_get_redis_client_logic(**env_overrides))
     verbose_logger.debug("get_redis_connection_pool: redis_kwargs", redis_kwargs)
 
     if "startup_nodes" in redis_kwargs: