pip(deps-dev): bump authlib from 0.15.5 to 0.15.6

Bumps [authlib](https://github.com/lepture/authlib) from 0.15.5 to 0.15.6.
- [Release notes](https://github.com/lepture/authlib/releases)
- [Changelog](https://github.com/lepture/authlib/blob/v0.15.6/docs/changelog.rst)
- [Commits](authlib/authlib@v0.15.5...v0.15.6)

---
updated-dependencies:
- dependency-name: authlib
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]