build: Bump arbitrary from 1.1.7 to 1.2.0 in /fuzz

Bumps [arbitrary](https://github.com/rust-fuzz/arbitrary) from 1.1.7 to 1.2.0.
- [Release notes](https://github.com/rust-fuzz/arbitrary/releases)
- [Changelog](https://github.com/rust-fuzz/arbitrary/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-fuzz/arbitrary/compare/v1.1.7...v1.2.0)

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

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

fuzz/Cargo.lock

@@ -24,9 +24,9 @@ dependencies = [
 
 [[package]]
 name = "arbitrary"
-version = "1.1.7"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d86fd10d912cab78764cc44307d9cd5f164e09abbeb87fb19fb6d95937e8da5f"
+checksum = "29d47fbf90d5149a107494b15a7dc8d69b351be2db3bb9691740e88ec17fd880"
 
 [[package]]
 name = "arc-swap"