Bump rayon from 1.7.0 to 1.8.0 in /src/agent (#3520)

Bumps [rayon](https://github.com/rayon-rs/rayon) from 1.7.0 to 1.8.0.
- [Changelog](https://github.com/rayon-rs/rayon/blob/master/RELEASES.md)
- [Commits](rayon-rs/rayon@rayon-core-v1.7.0...rayon-core-v1.8.0)

---
updated-dependencies:
- dependency-name: rayon
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/agent/Cargo.lock

@@ -13,7 +13,7 @@ fnv = "1.0"
 hex = "0.4"
 log = "0.4"
 num_cpus = "1.15"
-rayon = "1.7"
+rayon = "1.8"
 sha2 = "0.10.2"
 win-util = { path = "../win-util" }