Upgrade to Ruby 4.0

[sethboyles]

Tasks before we can upgrade Ruby 4.0

• Run units on various fog gems on Ruby 4.0 (and make PRs if necessary)
  • fog-local (this is development-only)
  • Azure
    • we maintain our own branch: https://github.com/fog/fog-azure-rm/tree/fog-arm-cf
    • untested against 4.0
  • S3/S3 compatible
    • They run units against 4.0: https://github.com/fog/fog-aws/actions/runs/25672704095/job/75361969390
  • GCS
    • They run units against 4.0 in their pipeline: https://github.com/fog/fog-google/commits/master/
  • Aliyun ?
    • failing tests against 4.0: https://github.com/fog/fog-aliyun/commits/master/
  • fog-core
    • They test Ruby 4.0 in CI: https://github.com/fog/fog-core/commits/master/
    • No release since it's been added, but no changes, either.
  • fog-json
    • They don't run CI for this, and I have the same tests failing for Ruby 3.2 and Ruby 3.3
  • fog-openstack
    • I couldn't get tests passing for this on either 3.2 or 3.3 (or 3.1)
• CATs/BARAs on Blobstores for Fog coverage
  • Azure
    • CATS
    • BARAS
  • S3/S3 compatible
    • CATS
    • BARAS
  • GCS
    • CATS
    • BARAS
  • Aliyun ?

Related Issues

cloudfoundry/cloud_controller_ng#5119
#648