chore(cargo): Bump config from 0.15.6 to 0.15.7

Bumps [config](https://github.com/rust-cli/config-rs) from 0.15.6 to 0.15.7.
- [Changelog](https://github.com/rust-cli/config-rs/blob/main/CHANGELOG.md)
- [Commits](rust-cli/config-rs@v0.15.6...v0.15.7)

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

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