Fix null repository agent attributes (#6560)

Repository responses can include null optional fields such as
`reasoning`. Treat them as omitted so Agent defaults apply instead of
failing validation.

lib/crewai/src/crewai/utilities/agent_utils.py

@@ -1150,6 +1150,8 @@ def load_agent_from_repository(from_repository: str) -> dict[str, Any]:
 
         agent = response.json()
         for key, value in agent.items():
+            if value is None:
+                continue
             if key == "tools":
                 attributes[key] = []
                 for tool in value:

lib/crewai/tests/agents/test_agent.py

@@ -2335,6 +2335,25 @@ def test_agent_from_repository_override_attributes(mock_get_agent, mock_get_auth
     assert isinstance(agent.tools[0], SerperDevTool)
 
 
+@patch("crewai.plus_api.PlusAPI.get_agent")
+def test_agent_from_repository_ignores_null_attributes(
+    mock_get_agent, mock_get_auth_token
+):
+    mock_get_response = MagicMock()
+    mock_get_response.status_code = 200
+    mock_get_response.json.return_value = {
+        "role": "test role",
+        "goal": "test goal",
+        "backstory": "test backstory",
+        "reasoning": None,
+    }
+    mock_get_agent.return_value = mock_get_response
+
+    agent = Agent(from_repository="test_agent")
+
+    assert agent.reasoning is False
+
+
 @patch("crewai.plus_api.PlusAPI.get_agent")
 def test_agent_from_repository_ignores_empty_skills(
     mock_get_agent, mock_get_auth_token