Have CI use newer versions of ruby and remove obsolete ones

[stevekeay]

The CI runner at github was failing on the older ruby versions:

Bundler 2 requires Ruby 2.3+, using Bundler 1 on Ruby <= 2.2
/opt/hostedtoolcache/Ruby/2.2.10/x64/bin/gem install bundler -v ~> 1.0
ERROR:  While executing gem ... (RuntimeError)

It was also failing to find the images:

Error: Unavailable version 9.2.21.0 for jruby on ubuntu-24.04 You can request it at https://github.com/ruby/setup-ruby/issues Cause: Unexpected HTTP response: 404 at /home/runner/work/_actions/ruby/setup-ruby/v1/dist/index.js:71342:15 at process.processTicksAndRejections (node:internal/process/task_queues:95:5) at async body (/home/runner/work/_actions/ruby/setup-ruby/v1/dist/index.js:355:14)
test (jruby-9.3.6.0)

Error: Unavailable version 9.3.6.0 for jruby on ubuntu-24.04 You can request it at https://github.com/ruby/setup-ruby/issues Cause: Unexpected HTTP response: 404 at /home/runner/work/_actions/ruby/setup-ruby/v1/dist/index.js:71342:15 at process.processTicksAndRejections (node:internal/process/task_queues:95:5) at async body (/home/runner/work/_actions/ruby/setup-ruby/v1/dist/index.js:355:14)

Error: Unavailable version 9.1.17.0 for jruby on ubuntu-24.04 You can request it at https://github.com/ruby/setup-ruby/issues Cause: Unexpected HTTP response: 404 at /home/runner/work/_actions/ruby/setup-ruby/v1/dist/index.js:71342:15 at process.processTicksAndRejections (node:internal/process/task_queues:95:5) at async body (/home/runner/work/_actions/ruby/setup-ruby/v1/dist/index.js:355:14)