ruby: fix postinstall

[chenrui333]

• Have you followed the guidelines for contributing?
• Have you ensured that your commits follow the commit style guide?
• Have you checked that there aren't other open pull requests for the same formula update/change?
• Have you built your formula locally with HOMEBREW_NO_INSTALL_FROM_API=1 brew install --build-from-source <formula>, where <formula> is the name of the formula you're submitting?
• Is your test running fine brew test <formula>, where <formula> is the name of the formula you're submitting?
• Does your build pass brew audit --strict <formula> (after doing HOMEBREW_NO_INSTALL_FROM_API=1 brew install --build-from-source <formula>)? If this is a new formula, does it pass brew audit --new <formula>?

---

seeing in #179326

  ==> An exception occurred within a child process:
    Errno::ENOENT: No such file or directory @ apply2files - /opt/homebrew/lib/ruby/gems/3.3.0/bin/bundle

[issyl0]

Sorry - and thank you!

[scpeters]

there are several other versioned ruby formulae that had a similar modification in #179161 that need this fix as well

[chenrui333]

doing the versioned formulae in #179335