Bump deps/coqutil from 9bb864c to 7ff6110

Bumps [deps/coqutil](https://github.com/mit-plv/coqutil) from `9bb864c` to `7ff6110`.
- [Release notes](https://github.com/mit-plv/coqutil/releases)
- [Commits](mit-plv/coqutil@9bb864c...7ff6110)

---
updated-dependencies:
- dependency-name: deps/coqutil
  dependency-type: direct:production
...

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