chore: use if TYPE_CHECKING: blocks (#2866)

cibuildwheel/environment.py

@@ -1,12 +1,18 @@
+from __future__ import annotations
+
 import dataclasses
-from collections.abc import Mapping, Sequence
-from typing import Any, Protocol
+from typing import Protocol
 
 import bashlex
 import bashlex.errors
 
 from cibuildwheel import bashlex_eval
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Mapping, Sequence
+    from typing import Any
+
 
 class EnvironmentParseError(Exception):
     pass