chore(deps): bump core-foundation-sys from 0.8.3 to 0.8.4

Bumps [core-foundation-sys](https://github.com/servo/core-foundation-rs) from 0.8.3 to 0.8.4.
- [Release notes](https://github.com/servo/core-foundation-rs/releases)
- [Commits](https://github.com/servo/core-foundation-rs/commits)

---
updated-dependencies:
- dependency-name: core-foundation-sys
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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