Make MyPy happy

Fixes for various type errors throw by mypy.

portal/api/auth.py

@@ -53,7 +53,7 @@ def require_valid(credential_type: type[User | Key]) -> Callable:
 
     def decorator(route: Callable) -> Callable:
         @functools.wraps(route)
-        def protected_route(**kwargs: Any) -> ProblemResponse:
+        def protected_route(**kwargs: Any) -> Any:
             # Determine which credentials to use
             credentials = {User: g.user, Key: g.key}.get(credential_type)