Support Ruby 4.0

[frederikspang]

[google-cla[bot]]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[JasonLunn]

This PR will need to wait until someone on the Protobuf team can do the internal housekeeping to verify that the changes to test_ruby.yml work as expected, because the current CI infrastructure ignores those changes from external contributors. I’ll be back online in the second week of January.

[JasonLunn]

Status update: Chasing down an issue with gem generation. Currently, everything works if the gem is build under an older version of Rubygems, but breaks under the latest version that ships with 4.0. Details: https://github.com/ruby/rubygems/pull/8569#issuecomment-3741647009

[JasonLunn]

See also the new tracking issue https://github.com/ruby/rubygems/issues/9244

[seuros]

Dont use the new version, it broken. Wait until 4.1.

Lock ci to use 2.x

[ashkulz]

@JasonLunn when can we expect a release which includes this?

[kapso]

@JasonLunn is there a release date for Ruby 4 support?

[kapso]

BTW I used the following and it works for us...

gem 'google-protobuf', force_ruby_platform: true

[seuros]

@kapso this is not a solution.. you will spend 40 minutes compiling this gem.

Fine in your local machine once.. good luck if you deploy often.