Rails 7.2 compatibility

[theodorton]

• Wrote good commit messages.
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests. - Not relevant; refactoring to support Rails 7.2
• Added an entry to the Changelog if the new
  code introduces user-observable changes. - Not relevant; refactoring to support Rails 7.2
• The PR relates to only one subject with a clear title
  and description in grammatically correct, complete sentences.

[fatkodima]

Can you please squash your commits into 1? You also need to update this line -

paper_trail/lib/paper_trail/compatibility.rb

Line 21 in 67a1ec2

ACTIVERECORD_LT = "< 7.2" # not enforced in gemspec

That CI failure regarding coverage - these coverage metrics are pretty pointless imo, I would prefer to just remove it from the project.

[theodorton]

I've fixed the compatibility spec, added the new appraisal to the CI matrix and squashed.