build(deps): bump spin from 0.9.4 to 0.9.8 in /boards/atsamv71_xult

Bumps [spin](https://github.com/mvdnes/spin-rs) from 0.9.4 to 0.9.8.
- [Changelog](https://github.com/mvdnes/spin-rs/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mvdnes/spin-rs/commits)

---
updated-dependencies:
- dependency-name: spin
  dependency-type: indirect
...

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