fix: correct patch path in langfuse test for MAX_LANGFUSE_INITIALIZED_CLIENTS (#13192)

The test was failing because it was trying to patch MAX_LANGFUSE_INITIALIZED_CLIENTS
at the wrong path. The constant is imported from litellm.constants into the langfuse
module namespace, so we need to use patch.object on the imported module reference.

Changes:
- Import langfuse module explicitly for patching
- Use patch.object instead of patch string path
- This fixes the AttributeError that was causing CI failures

tests/test_litellm/integrations/test_langfuse.py

@@ -12,6 +12,7 @@ from unittest.mock import patch
 import pytest
 
 import litellm
+from litellm.integrations.langfuse import langfuse as langfuse_module
 from litellm.integrations.langfuse.langfuse import LangFuseLogger
 
 
@@ -20,9 +21,7 @@ def test_max_langfuse_clients_limit():
     Test that the max langfuse clients limit is respected when initializing multiple clients
     """
     # Set max clients to 2 for testing
-    with patch(
-        "litellm.integrations.langfuse.langfuse.MAX_LANGFUSE_INITIALIZED_CLIENTS", 2
-    ):
+    with patch.object(langfuse_module, "MAX_LANGFUSE_INITIALIZED_CLIENTS", 2):
         # Reset the counter
         litellm.initialized_langfuse_clients = 0