Add Redhat container image to gitlab-workspace-docs container registry
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MR: Pending
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## Description
As a developer, I want to have a working Redhat Enterprise Linux based container image so that i can quickly test workspace related changes/bugs/gem builds in the RH environment. We already have several container images for debian/ubuntu but it would be nice if we have coverage for Redhat as well.
This decision is based on the discussion here: https://gitlab.com/gitlab-org/gitlab/-/issues/522971#note_2469097249
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## Acceptance criteria
- [ ] A RHEL 8.x or greater with x86_64 arch container image
- [ ] Should support sudo access
- [ ] Should come with some basic tools preinstalled like `git, bundler, ruby, nano/vim`
- [ ] Container image uploaded to https://gitlab.com/gitlab-org/workspaces/gitlab-workspaces-docs/container_registry
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