Fix linting issues in test file

Co-Authored-By: Joe Moura <joao@crewai.com>

tests/knowledge/test_string_knowledge_source_fix.py

@@ -1,9 +1,12 @@
+from unittest.mock import MagicMock, patch
+
 import pytest
-from unittest.mock import patch, MagicMock
-from crewai import Agent, Task, Crew, Process
+
+from crewai import Agent, Crew, Process, Task
 from crewai.knowledge.source.string_knowledge_source import StringKnowledgeSource
 from crewai.knowledge.storage.knowledge_storage import KnowledgeStorage
 
+
 def test_knowledge_storage_search_filtering():
     """Test that KnowledgeStorage.search() correctly filters results based on distance scores."""
     # Create a mock collection to simulate ChromaDB behavior