Bump commons from 83d9da9 to d8a1d0a (#931)

Bumps [commons](https://github.com/heroku/buildpacks-ruby) from `83d9da9` to `d8a1d0a`.
- [Release notes](https://github.com/heroku/buildpacks-ruby/releases)
- [Commits](heroku/buildpacks-ruby@83d9da9...d8a1d0a)

---
updated-dependencies:
- dependency-name: commons
  dependency-type: direct:production
...

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