How to upgrade omnibus 11.8 to most recent version

I have an ominbus package 10.8.1 on Ubuntu 14.04 (aka old server). I am trying to ultimately get to 12.2 on a new Ubuntu 18.0.4 server(aka new server). My plan has been to upgrade to gitlab 12.2 on the old server, then create a backup of that to migrate to the new server.

On the older server I ran:

sudo apt-get update
sudo apt-get install gitlab-ce

That upgraded gitlab to 11.10.8. But now I cannot find any information about how to upgrade further. I re-installed the repo to make sure I have the latest version:

$ curl https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh | sudo bash
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  5933    0  5933    0     0  18346      0 --:--:-- --:--:-- --:--:-- 18368
Detected operating system as Ubuntu/trusty.
Checking for curl...
Detected curl...
Checking for gpg...
Detected gpg...
Running apt-get update... done.
Installing apt-transport-https... done.
Installing /etc/apt/sources.list.d/gitlab_gitlab-ce.list...done.
Importing packagecloud gpg key... done.
Running apt-get update... done.

The repository is setup! You can now install packages.

But I cannot upgrade to anything newer:

sudo apt-get install gitlab-ce
Reading package lists... Done
Building dependency tree       
Reading state information... Done
gitlab-ce is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 250 not upgraded.

sudo apt-get install gitlab-ce=11.11.2-ce.0
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Version '11.11.2-ce.0' for 'gitlab-ce' was not found

Ubuntu stopped supporting 14.04 earlier this year, and GitLab stopped releasing packages of new versions for it at about the same time, so there are no official omnibus packages of later versions for ubuntu 14.04.

Your best bet is probably to install the new server with 11.10.8, restore a backup to it and upgrade it immediately.