Retire <2.7 and add 3.0-3.3

[tpowell-progress]

Description

Ruby 2.4 and 2.5 are broken due to public_suffix-5.0.4 requires ruby version >= 2.6, but also need to retire builders EOLed rubies. Keeping 2.7 around for now until some pull requests can get caught up first.

Related Issue

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (non-breaking change that does not add functionality or fix an issue)

Checklist:

• I have read the CONTRIBUTING document.
• I have run the pre-merge tests locally and they pass.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• If Gemfile.lock has changed, I have used --conservative to do it and included the full output in the Description above.
• All new and existing tests passed.
• All commits have been signed-off for the Developer Certificate of Origin.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[Fs00]

@tpowell-progress Please be aware that this gem is broken on Ruby 3+ too, because rexml is not listed among the dependencies (though it works if rexml is pulled in by another dependency).
I've opened #169 to add rexml to the gemspec (you can find a bit more context there), but feel free to close it and apply the change here.