Bump spin from 0.9.4 to 0.9.8

Bumps [spin](https://github.com/mvdnes/spin-rs) from 0.9.4 to 0.9.8.
- [Release notes](https://github.com/mvdnes/spin-rs/releases)
- [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: direct:production
...

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

Cargo.toml

@@ -99,7 +99,7 @@ sha2 = { version = "0.10", default-features = false }
 sha3 = { version = "0.10", default-features = false }
 smbus-pec = { version = "1.0.1", default-features = false }
 smoltcp = { version = "0.8.0", default-features = false, features = ["proto-ipv6", "medium-ethernet", "socket-udp", "async"] }
-spin = { version = "0.9.4", default-features = false, features = ["mutex", "spin_mutex"]}
+spin = { version = "0.9.8", default-features = false, features = ["mutex", "spin_mutex"]}
 ssmarshal = { version = "1.0.0", default-features = false }
 static_assertions = { version = "1", default-features = false }
 stm32f3 = { version = "0.13.0", default-features = false }