Is your feature request related to a problem? Please describe.
We currently have rigid requirements around minimum supported OS versions, but have no automated tests running against these versions.

Describe the solution you'd like
We should add github actions for compilation and testing on all minimum supported platform versions.

Describe alternatives you've considered
We could:

1. not test, which in the best case degrades the feedback loop for contributors, and at worst will break our support for whatever platform
2. test in some other way than Github actions, which is legitimate, but Github actions are already in use and are fairly convenient

Additional context
n/a