fix upstash test import (#11781)

libs/langchain/tests/integration_tests/storage/test_upstash_redis.py

@@ -1,10 +1,15 @@
 """Implement integration tests for Redis storage."""
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
 
 import pytest
-from upstash_redis import Redis
 
 from langchain.storage.upstash_redis import UpstashRedisStore
 
+if TYPE_CHECKING:
+    from upstash_redis import Redis
+
 pytest.importorskip("upstash_redis")
 
 URL = "<UPSTASH_REDIS_REST_URL>"