Onboard onto IBM-provided GitHub Actions runners for Power and Z

[jiridanek]

Linking in case this is alternatively useful (GitHub Actions runners for Power and Z)
https://community.ibm.com/community/user/blogs/elizabeth-k-joseph1/2025/05/19/expanding-open-source-access-hosted-github-actions

https://issues.redhat.com/browse/RHOAIENG-37849?focusedId=28452351&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-28452351

This is alternative to

• onboarding to TravisCI, Onboard onto Travis CI Partner Queue #2632
• implementing cross-compilation with zig cc, introduce zig cc cross-compilation setup for GitHub Actions and local development #2535

Thanks @grdryn for pointing out the option.

[jiridanek]

Created onboarding request

• New Project: opendatahub-io/notebooks IBM/actionspz#63