Disallow bundle to any changes to Gemfile.lock

What does this MR do?

Per the Rubygems.org advisory, we should be using frozen on CI

https://github.com/rubygems/rubygems.org/security/advisories/GHSA-hccv-rwq6-vh79

Not that I also had to add a command to install the locked Bundler version (2.2.33) on our CI, so that frozen does not complain, since the Ruby image on our CI has an older version of Bundler.

FYI, @tkuah.

Related issues

Related to #6821 (closed)

Checklist

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