build(deps): bump der from 0.6.0 to 0.6.1

Bumps [der](https://github.com/RustCrypto/formats) from 0.6.0 to 0.6.1.
- [Release notes](https://github.com/RustCrypto/formats/releases)
- [Commits](RustCrypto/formats@der/v0.6.0...der/v0.6.1)

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

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