build: cleanup and sort imports
# See the License for the specific language governing permissions and
# limitations under the License.
-import copy, os, re
from collections import OrderedDict, defaultdict
-import itertools, pathlib
+from functools import lru_cache
+import copy
import hashlib
+import itertools, pathlib
+import os
import pickle
-from functools import lru_cache
+import re
import typing as T
from . import environment
