Prepare Ruby3 scheduled pipeline for JH

Upstream Epic: https://gitlab.com/groups/gitlab-org/-/epics/8101

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In order to meet the upcoming Ruby 3 upgrade, JH also prepares the relevant test environment and cache plan in advance.

Related Issue: https://gitlab.com/gitlab-jh/gitlab-jh-enablement/-/issues/259

Upstream Scheduled pipelines: https://gitlab.com/gitlab-org/gitlab/-/pipeline_schedules