fix: resolve import sorting issues in agent.py and test_agent.py

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

tests/test_agent.py

@@ -1,10 +1,12 @@
 import os
-import pytest
 from unittest import mock
 
+import pytest
+
 from crewai.agent import Agent
 from crewai.llm import LLM
 
+
 def test_agent_with_custom_llm():
     """Test creating an agent with a custom LLM."""
     custom_llm = LLM(model="gpt-4")