CU-8695hghww backwards compatibility workflow

[mart-r]

Add a new step to GHA workflow that does the following:

• Downloads all (fake) models for various versions
  • 1.2.9, 1.3.1, 1.4.1, 1.5.3, 1.6.1, 1.7.0, 1.8.0, 1.9.0, 1.10., 1.11.0, 1.12.0
  • These are fake models created with the fake data as per #470
  • They do not contain MetaCATs or RelCATs
• Makes sure they all work
  • Runs each model through the fake-model based regression suite as per #470
  • This is to ensure they all run, at least in principle
• Cleans up afterwards

This PR depends on #470 and the GHA workflow will fail without it having been merged in since some of the necessary parts don't exist or are in a different state.

NOTE: Perhaps I'd want to include some (basic) legacy DeID models as well to make sure that works?