Bump joserfc from 1.6.5 to 1.6.8

Bumps [joserfc](https://github.com/authlib/joserfc) from 1.6.5 to 1.6.8.
- [Release notes](https://github.com/authlib/joserfc/releases)
- [Changelog](https://github.com/authlib/joserfc/blob/main/docs/changelog.rst)
- [Commits](authlib/joserfc@1.6.5...1.6.8)

---
updated-dependencies:
- dependency-name: joserfc
  dependency-version: 1.6.8
  dependency-type: indirect
...

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Author: dependabot[bot]