FIX Only change constraints for recipes

[GuySartorelli]

Bad logic in cow resulted in many non-recipes having their constraints updated automatically when the beta was released.
Only recipes should have their constraints updated.

Issue

• Cow - work out why non-recipes ended up with new deps .github#33

[maxime-rainville]

Code looks good and sensible. I'm assuming you tried this locally and are confident it will work?

[GuySartorelli]

I am confident it'll work. But I can't do a dry run with it until the PRs are merged that set the correct constraints to start with.
Once those are merged I'll do a dry run.

[GuySartorelli]

This has been approved and I've confirmed in a dry-run that it works as expected.
Merging.