Bump rustversion from 1.0.15 to 1.0.17

Bumps [rustversion](https://github.com/dtolnay/rustversion) from 1.0.15 to 1.0.17.
- [Release notes](https://github.com/dtolnay/rustversion/releases)
- [Commits](dtolnay/rustversion@1.0.15...1.0.17)

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

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