refactor: tomllib in _compat

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

bin/update_pythons.py

@@ -5,7 +5,6 @@ from __future__ import annotations
 import copy
 import difflib
 import logging
-import sys
 from collections.abc import Mapping, MutableMapping
 from pathlib import Path
 from typing import Any, Union
@@ -13,17 +12,12 @@ from typing import Any, Union
 import click
 import requests
 import rich
-
-if sys.version_info >= (3, 11):
-    import tomllib
-else:
-    import tomli as tomllib
-
 from packaging.specifiers import Specifier
 from packaging.version import Version
 from rich.logging import RichHandler
 from rich.syntax import Syntax
 
+from cibuildwheel._compat import tomllib
 from cibuildwheel._compat.typing import Final, Literal, TypedDict
 from cibuildwheel.extra import dump_python_configurations