In addition to adding 3.1 and jruby-9.3, we quote '3.0' to ensure that it is not truncated to 3. An unquoted 3.0 will be truncated to 3, and will load the latest Ruby 3 - which at time of writing is 3.1.0. To ensure a Ruby 3.0.x is loaded we need to quote it.
Add Ruby 3.1 and jruby-9.3 to the CI matrix.
In addition to adding 3.1 and jruby-9.3, we quote '3.0' to ensure that it is not truncated to 3. An unquoted 3.0 will be truncated to 3, and will load the latest Ruby 3 - which at time of writing is 3.1.0. To ensure a Ruby 3.0.x is loaded we need to quote it.