chore(deps): Bump cc from 1.1.20 to 1.1.21 in /fuzz/aflplusplus

Bumps [cc](https://github.com/rust-lang/cc-rs) from 1.1.20 to 1.1.21.
- [Release notes](https://github.com/rust-lang/cc-rs/releases)
- [Changelog](https://github.com/rust-lang/cc-rs/blob/main/CHANGELOG.md)
- [Commits](rust-lang/cc-rs@cc-v1.1.20...cc-v1.1.21)

---
updated-dependencies:
- dependency-name: cc
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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