build(deps): bump third_party/tools/slang from 9b3e779 to f4e8ec4

Bumps [third_party/tools/slang](https://github.com/MikePopoloski/slang) from `9b3e779` to `f4e8ec4`.
- [Release notes](https://github.com/MikePopoloski/slang/releases)
- [Commits](MikePopoloski/slang@9b3e779...f4e8ec4)

---
updated-dependencies:
- dependency-name: third_party/tools/slang
  dependency-type: direct:production
...

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