Describe the bug

Keyring fails to be imported in Python 3.8+ due to this import:

Since that functionality is part of the standard library in Python 3.8+, it needs to written as

import importlib.metadata as metadata

for those versions (I understand the import is correct for older ones).

To Reproduce
Steps to reproduce the behavior:

1. Install Keyring 22.4.0 or later in Python 3.8+
2. Open a Python interpreter
3. import keyring

Expected behavior
Keyring shouldn't fail when imported.

Environment

• OS: Any operating system. This was discovered in Conda-forge when creating packages for Keyring:

  keyring v22.4.0 conda-forge/keyring-feedstock#62