Use zoneinfo from stdlib rather than backports library

requirements/requirements.txt

@@ -1,10 +1,6 @@
 Pillow
 VWS-Auth-Tools
-# We add ``[tzdata]`` for Windows.
-# Building the wheel for this on Apple Silicon needs ``gcc`` - that is
-# hardcoded in the base Dockerfile.
-# This can be removed when we only support Python 3.9+.
-backports.zoneinfo[tzdata]
 flask
 requests-mock
 requests
+tzdata; sys_platform == 'win32'

src/mock_vws/_flask_server/dockerfiles/base/Dockerfile

@@ -1,9 +1,7 @@
 FROM python:3.9.1-slim-buster
 RUN apt update --yes
 # git is needed for setuptools-scm.
-# gcc is needed to create the wheel for backports.zoneinfo, at least on Apple
-# Silicon.
-RUN apt install --yes git gcc
+RUN apt install --yes git
 COPY . /app
 WORKDIR /app
 RUN pip install .

src/mock_vws/_flask_server/target_manager.py

@@ -8,8 +8,8 @@
 import random
 from http import HTTPStatus
 from typing import Tuple
+from zoneinfo import ZoneInfo
 
-from backports.zoneinfo import ZoneInfo
 from flask import Flask, jsonify, request
 
 from mock_vws.database import VuforiaDatabase

src/mock_vws/_query_tools.py

@@ -10,8 +10,7 @@
 import io
 import uuid
 from typing import Any, Dict, Set
-
-from backports.zoneinfo import ZoneInfo
+from zoneinfo import ZoneInfo
 
 from mock_vws._base64_decoding import decode_base64
 from mock_vws._constants import ResultCodes, TargetStatuses

src/mock_vws/_query_validators/date_validators.py

@@ -4,8 +4,7 @@
 
 import datetime
 from typing import Dict, Set
-
-from backports.zoneinfo import ZoneInfo
+from zoneinfo import ZoneInfo
 
 from mock_vws._query_validators.exceptions import (
     DateFormatNotValid,

src/mock_vws/_requests_mock_server/mock_web_services_api.py

@@ -15,8 +15,8 @@
 import uuid
 from http import HTTPStatus
 from typing import Callable, Dict, Set
+from zoneinfo import ZoneInfo
 
-from backports.zoneinfo import ZoneInfo
 from requests_mock import DELETE, GET, POST, PUT
 from requests_mock.request import _RequestObjectProxy
 from requests_mock.response import _Context

src/mock_vws/_services_validators/date_validators.py

@@ -5,8 +5,7 @@
 import datetime
 from http import HTTPStatus
 from typing import Dict
-
-from backports.zoneinfo import ZoneInfo
+from zoneinfo import ZoneInfo
 
 from mock_vws._services_validators.exceptions import Fail, RequestTimeTooSkewed
 

src/mock_vws/target.py

@@ -11,8 +11,8 @@
 import uuid
 from dataclasses import dataclass, field
 from typing import TypedDict
+from zoneinfo import ZoneInfo
 
-from backports.zoneinfo import ZoneInfo
 from PIL import Image, ImageStat
 
 from mock_vws._constants import TargetStatuses

tests/mock_vws/test_date_header.py

@@ -6,10 +6,10 @@
 from http import HTTPStatus
 from typing import Dict
 from urllib.parse import urlparse
+from zoneinfo import ZoneInfo
 
 import pytest
 import requests
-from backports.zoneinfo import ZoneInfo
 from freezegun import freeze_time
 from requests.structures import CaseInsensitiveDict
 from vws_auth_tools import authorization_header, rfc_1123_date

tests/mock_vws/test_invalid_json.py

@@ -5,10 +5,10 @@
 from datetime import datetime, timedelta
 from http import HTTPStatus
 from urllib.parse import urlparse
+from zoneinfo import ZoneInfo
 
 import pytest
 import requests
-from backports.zoneinfo import ZoneInfo
 from freezegun import freeze_time
 from requests.structures import CaseInsensitiveDict
 from vws_auth_tools import authorization_header, rfc_1123_date

tests/mock_vws/test_query.py

@@ -17,10 +17,10 @@
 from pathlib import Path
 from typing import Any, Dict
 from urllib.parse import urljoin
+from zoneinfo import ZoneInfo
 
 import pytest
 import requests
-from backports.zoneinfo import ZoneInfo
 from PIL import Image
 from requests import Response
 from requests_mock import POST

tests/mock_vws/test_target_summary.py

@@ -5,10 +5,10 @@
 import datetime
 import io
 import uuid
+from zoneinfo import ZoneInfo
 
 import pytest
 from _pytest.fixtures import SubRequest
-from backports.zoneinfo import ZoneInfo
 from vws import VWS, CloudRecoService
 from vws.exceptions.vws_exceptions import UnknownTarget
 from vws.reports import TargetStatuses

tests/mock_vws/utils/assertions.py

@@ -10,8 +10,8 @@
 import json
 from http import HTTPStatus
 from string import hexdigits
+from zoneinfo import ZoneInfo
 
-from backports.zoneinfo import ZoneInfo
 from requests import Response
 
 from mock_vws._constants import ResultCodes