If there's no cost in time, effort or equipment then mirror it yourself. It's easy, right?
Or just use an LTS distro like literally every single other organization that depends on Ubuntu for their business SMH. Like, it's absurd to even think about...
Anyhow someone else showed they do indeed host old repos, just in a different place. Also, why can't you update? Who the hell made that contract? And is it the client the said you can't update or Canonical? Because the latter seems sus...
Or just use an LTS distro like literally every single other organization that depends on Ubuntu for their business SMH. Like, it's absurd to even think about...