Wrong version of database, Gitlab still works, no backups, Upgrade does not work

TLDR; Gitlab 13.1.11 on Postgres 12.5 wont upgrade. Looking to clone production to the UAT server so I can mess with it to figure it out. Backup wont work on production due to pg_dump mismatch. Looking for a jumpstart on manually backing up a GitlabCE db from 12.5 using PGDUMP and restoring to a 11.7 server. Hopefully fixing the DB migrations problem in the process.

Can I just copy over the Gitlab data folder, and the db to a different server modify my compose file and it will start? I guess manually backing up the contents of the production server.

Long Version

Well life has gone sideways,

We had a 10.x version of Gitlab CE running on a Docker machine with an old PSQL 9 server as the DB. I was asked by the Team lead to upgrade to latest to appease the security group. I requested a DB upgrade from our Data Group and received a PSQL 12.5 Server. I provisioned a new Docker server to create a whole new environment.

I didn’t think anything of it and did normal GitLab backup and restored to the new environment with the same Gitlab version and then upgraded it all the way up to GitlabCE 13.1.11. I had an issue at that point with the upgrade past that point failing and stopped there. Manager decided to stick with that for a bit till we could cycle back to it. We tested for a couple of weeks, all was good (and still in operation) and deprecated the old system.

Fast forward till a couple weeks back where the upgrade process was back on the work sheet. Went to do a backup of the production data so I can restore to the UAT server and it failed with;

Dumping PostgreSQL database gitlab_fin_prod … pg_dump: server version: 12.5; pg_dump version: 11.7
pg_dump: aborting because of server version mismatch

So after a bunch of research, a bit of cursing and the realization that the DB server was not the correct version for the Gitlab instance I am at the point of figuring out how to upgrade to current version of Gitlab CE from 13.1.11.

The standard upgrade path fails at the migration, I can dump the error if anybody is interested.