TASK: Remove ResilientStorage variant

[yselkowitz]

What does the ELN SIG need to do?

The ResilientStorage (RS) variant has been dropped from c10s composes; ELN should follow suit.

• [x] Content Resolver input: https://github.com/minimization/content-resolver-input/pull/1300
• [x] Content Resolver test configs
• [x] pungi-configs: included in https://pagure.io/pungi-fedora/pull-request/1393
• [x] fedora-comps
• [x] fedora-repos
• [x] mock-core-configs
• [ ] mirrormanager configuration
• [ ] what else?

[sgallagher]

fedora-comps: https://pagure.io/fedora-comps/pull-request/1040

[sgallagher]

fedora-repos: https://src.fedoraproject.org/rpms/fedora-repos/pull-request/150

[yselkowitz]

https://github.com/minimization/content-resolver/pull/70

[yselkowitz]

https://github.com/rpm-software-management/mock/pull/1492

[yselkowitz]

mirrors: https://github.com/fedora-infra/mirrormanager2/issues/409