Bump keyring from 21.7.0 to 21.8.0

Bumps [keyring](https://github.com/jaraco/keyring) from 21.7.0 to 21.8.0.
- [Release notes](https://github.com/jaraco/keyring/releases)
- [Changelog](https://github.com/jaraco/keyring/blob/main/CHANGES.rst)
- [Commits](jaraco/keyring@v21.7.0...v21.8.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

dev-requirements.txt

@@ -13,7 +13,7 @@ flake8-quotes==3.2.0  # Require single quotes
 flake8==3.8.4  # Lint
 freezegun==1.0.0  # Freeze time in tests
 isort==5.6.4  # Lint imports
-keyring==21.7.0
+keyring==21.8.0
 mypy==0.790 # Type checking
 pip_check_reqs==2.1.1
 pydocstyle==5.1.1  # Lint docstrings