fix: add type:ignore for kubernetes imports in all files

mypy attr-defined errors on 'from kubernetes import config/client'
in request_upgrades.py and web.py — same fix already applied to
check_versions.py.

request_upgrades.py

@@ -18,7 +18,7 @@ from datetime import datetime, timezone
 from pathlib import Path
 
 import requests
-from kubernetes import config
+from kubernetes import config  # type: ignore[attr-defined]
 from packaging.version import Version, InvalidVersion
 
 from check_versions import (