Fix all lint errors (#2627)

tests/llms/test_azure_openai.py

@@ -1,6 +1,5 @@
 from unittest.mock import Mock, patch
 
-import httpx
 import pytest
 
 from mem0.configs.llms.base import BaseLlmConfig

tests/llms/test_deepseek.py

@@ -1,5 +1,6 @@
-from unittest.mock import Mock, patch
 import os
+from unittest.mock import Mock, patch
+
 import pytest
 
 from mem0.configs.llms.base import BaseLlmConfig

tests/llms/test_langchain.py

@@ -1,4 +1,5 @@
-from unittest.mock import Mock, patch
+from unittest.mock import Mock
+
 import pytest
 
 from mem0.configs.llms.base import BaseLlmConfig

tests/llms/test_openai.py

@@ -1,5 +1,6 @@
-from unittest.mock import Mock, patch
 import os
+from unittest.mock import Mock, patch
+
 import pytest
 
 from mem0.configs.llms.base import BaseLlmConfig