Fix impossible _Env import

Author: Avasam

distutils/spawn.py

@@ -13,13 +13,16 @@
 import sys
 import warnings
 from collections.abc import Mapping, MutableSequence
-from subprocess import _ENV
-from typing import TypeVar, overload
+from typing import TYPE_CHECKING, TypeVar, overload
 
 from ._log import log
 from .debug import DEBUG
 from .errors import DistutilsExecError
 
+if TYPE_CHECKING:
+    from subprocess import _ENV
+
+
 _MappingT = TypeVar("_MappingT", bound=Mapping)