Migrate legacy koji.mbox infra env to different infra

Per public announce (https://lists.centos.org/pipermail/centos-devel/2023-February/142762.html) the https://koji.mbox.centos.org build infra (kojihub/mbs/odcs/kojid builders, compose machines) is set to read-only, while the workload was migrated to https://kojihub.stream.rdu2.redhat.com/koji/ (external name being https://kojihub.stream.centos.org/koji/)

We can now reclaim/recycle some of the items used in that setup, and unused anymore (and optimized resources in that DC).

Tasks overview:

• disable all kojid builders in existing kojihub
• install a rhel8 kojihub VM, accessing NFS and same postgresql DB
• update DB schema to match installed koji version
• decommission old container based koji stack (running on centos7/okd 3.11)
• reclaim all kojid machines (recycled for other purposes)
• run koji-gc on existing setup to minimize disk usage (really high and we have backups)
• move koji volume to different (slower/trimmed NFS volume)
• reclaim existing storage space and reuse for other purposes

Just creating one ticket for this, instead of plenty of sub-tasks but I'll work on this in parallel of other tasks, as it's not high priority (from Stream infra perspective) but still good to do as we need storage resources for community facing cbs.centos.org kojihub infra