fix(test): skip MCP tests on Python 3.9

The MCP module is only available on Python 3.10+. Add skipif marker
to TestFetchMcpToolsInternal class to prevent ModuleNotFoundError
on Python 3.9 CI runs.

Author: ryoppippi

tests/test_toolset_mcp.py

@@ -1,12 +1,16 @@
 from __future__ import annotations
 
+import sys
 from contextlib import asynccontextmanager
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
 from stackone_ai.toolset import StackOneToolSet, _fetch_mcp_tools, _McpToolDefinition
 
+# MCP module requires Python 3.10+
+SKIP_MCP_TESTS = sys.version_info < (3, 10)
+
 
 @pytest.fixture
 def mock_mcp_catalog(monkeypatch):
@@ -323,6 +327,7 @@ def fake_fetch(_: str, headers: dict[str, str]) -> list[_McpToolDefinition]:
             toolset.fetch_tools()
 
 
+@pytest.mark.skipif(SKIP_MCP_TESTS, reason="MCP module requires Python 3.10+")
 class TestFetchMcpToolsInternal:
     """Test _fetch_mcp_tools internal implementation."""