`stack-upload-action` was updated recently to add this env variable. The main `stack.yaml` should be used for release purposes. Since `working-directory` is in each package of the monorepo, `stack` needs to look up a directory for this file.

Using a relative path is a bit fragile but there doesn't appear to be a variable used to refer to the project root to avoid it.

🤦‍♂️ Of course the previous commit fixing the release workflow won't run if it doesn't see the version has increased.

This allows testing back to lts-12.26 / ghc-8.4. We were already doing
CPP in this module for another change, so this is pretty low effort once
tracked down.

In newer GHCs, the order of these appears to matter and we must derive
field types for record types that use them.

And adjust indentation.

- Use versioned actions
- Don't re-specify default lower bounds
- Use oldest LTS so we get lowest lower bounds