fix: use ops+robot as git user for all ci

[lukekarrys]

I'm not sure if we want to do this, or if there was a reason to keep these bot users separate.

This would change the git user of all our CI commits to @npm-robot. This is the user we use to create PRs to nodejs/node (nodejs/node#42550) and add benchmark comments (npm/cli#4716 (comment)).

[wraithgar]

I think the intention was to separate the registry team's automated actions from the cli team's. @darcyclarke may have more context there.

[lukekarrys]

We also have https://github.com/npm-deploy-user that is used to deploy the statusboard (maybe more?).

The only thing I want from this is for the user that creates commits in the cli to have a GitHub profile like the others. So if we want to keep them separate that can still be accomplished.

[wraithgar]

Moving it in this direction is probably still the right choice. Separating them out can be a future concern.