simplify handling of importlib-metadata.version

src/poetry/__version__.py

@@ -1,16 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
-
 from poetry.utils._compat import metadata
 
 
-if TYPE_CHECKING:
-    from collections.abc import Callable
-
-
-# The metadata.version that we import for Python 3.7 is untyped, work around
-# that.
-version: Callable[[str], str] = metadata.version
-
-__version__ = version("poetry")
+__version__ = metadata.version("poetry")