Remove `update-from-workflow`

[lwjohnst86]

So far, it doesn't work as I was thinking it might (or rather, its a bit more complicated). I think it's a fine workflow to update from the template manually whenever working on the repo (e.g. since we have a justfile recipe for it). If the workflow is running regularly to check if it needs to sycnh, it means that if we have a change in the template and it breaks or something, it will require our direct attention and involvement to resolve the synch in a repo. I'd personally rather deal with issues in a repo when we are actually working on it and have planned time to work on it, rather than being forced to work on it whenever a sync happens and does more than just "sync" things.