Trigger prod deploys on new `v*` tags

[mxmeinhold]

Turns out, you can trigger workflow's on tag pushes (I've learned this setting up the CD for https://github.com/mxmeinhold/pylint-fixme-info and https://github.com/mxmeinhold/decision-tree).

This pr should be the last step before we can drop this double branch setup, and move to prod being reflected by tags.