Bump config from 0.15.8 to 0.15.9

Bumps [config](https://github.com/rust-cli/config-rs) from 0.15.8 to 0.15.9.
- [Changelog](https://github.com/rust-cli/config-rs/blob/main/CHANGELOG.md)
- [Commits](rust-cli/config-rs@v0.15.8...v0.15.9)

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

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

Author: dependabot[bot]