Testing env improvements - add test environments and bump versions

[sergioisidoro]

Some housekeeping:

• Bumps patch and minor versions on test matrix
• Adds Rails 7 to test matrix
• Adds Ruby 3.0 and 3.1 ( Excluding older Rails versions from tests in Ruby 3.x )
  • Docs for excluding envs here
• Adds some annotations about EOLs of testing environments
• Adds a Docker and Docker compose to easily debug in any environment (ARM64 makes it sometimes tricky to use older Ruby versions)
• Removes truffleruby-head from the test matrix as it was a bit discussed on the PRs Greg authored. -- eg Fix truffleruby workflow #479 (comment)

[sergioisidoro]

            LoadError:
              cannot load such file -- net/smtp

Potentially an upstream problem - https://stackoverflow.com/a/70500221/2943164

[sergioisidoro]

NameError:
  uninitialized constant ActiveSupport::XmlMini::IsolatedExecutionState

Some more upstream issues rails/rails#43851

[sergioisidoro]

@BookOfGreg At least test suite is now green with Rails 7 🎉
Some significant issues upstream were fount, but have patches, but I think they are not relevant to the gem itself.

Let me know if this is enough to get this forward, and sorry for the duplicate work that you started.

[sergioisidoro]

I kind of deprecated Rails 3 and 4 here.
But as Rails 5 is reaching its end of life I think it's quite reasonable (besides it's not tested)

[BookOfGreg]

Yes they're out of support by Rails so they're good to drop.

[BookOfGreg]

Thanks for repairing and adding to the test suite here.

[BookOfGreg]

Yes they're out of support by Rails so they're good to drop.

[BookOfGreg]

Good move for local convenience 👍