Remove import sys and skip decorators from test files

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

tests/crew_test.py

@@ -3,7 +3,6 @@
 import hashlib
 import json
 import os
-import sys
 from concurrent.futures import Future
 from unittest import mock
 from unittest.mock import MagicMock, patch

tests/knowledge/knowledge_test.py

@@ -1,6 +1,5 @@
 """Test Knowledge creation and querying functionality."""
 
-import sys
 from pathlib import Path
 from typing import List, Union
 from unittest.mock import patch