disable flake warnings for unused imports of types

lib/spack/spack/builder.py

@@ -6,7 +6,7 @@
 import copy
 import functools
 import inspect
-from typing import List, Optional, Tuple
+from typing import List, Optional, Tuple  # noqa: F401
 
 import six
 

lib/spack/spack/database.py

@@ -26,7 +26,7 @@
 import socket
 import sys
 import time
-from typing import Dict  # novm
+from typing import Dict  # novm # noqa: F401
 
 import six
 

lib/spack/spack/package_base.py

@@ -27,7 +27,16 @@
 import traceback
 import types
 import warnings
-from typing import Any, Callable, Dict, Iterable, List, Optional, Tuple, Type  # novm
+from typing import (  # novm # noqa: F401
+    Any,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    Tuple,
+    Type,
+)
 
 import six