Reverted typechecker-only import

Author: agronholm

setuptools/command/editable_wheel.py

@@ -59,7 +59,7 @@
 from .install_scripts import install_scripts as install_scripts_cls
 
 if TYPE_CHECKING:
-    from ..extern.wheel.wheelfile import WheelFile  # type:ignore[import-untyped]
+    from .._vendor.wheel.wheelfile import WheelFile  # type:ignore[import-untyped]
 
 _P = TypeVar("_P", bound=StrPath)
 _logger = logging.getLogger(__name__)