Bump portable-atomic from 1.6.0 to 1.7.0 in /src/rust

Bumps [portable-atomic](https://github.com/taiki-e/portable-atomic) from 1.6.0 to 1.7.0.
- [Release notes](https://github.com/taiki-e/portable-atomic/releases)
- [Changelog](https://github.com/taiki-e/portable-atomic/blob/main/CHANGELOG.md)
- [Commits](taiki-e/portable-atomic@v1.6.0...v1.7.0)

---
updated-dependencies:
- dependency-name: portable-atomic
  dependency-type: indirect
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>