Bump cryptography from 3.4.7 to 3.4.8 (#1837)

Bump cryptography from 3.4.7 to 3.4.8 (#1837)

Bumps [cryptography](https://github.com/pyca/cryptography) from 3.4.7 to 3.4.8.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/main/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/3.4.7...3.4.8)

---
updated-dependencies:
- dependency-name: cryptography
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: Tom Christie <tom@tomchristie.com>