Switch to a different translation service #1494
Description
The onesky link in the README is dead (domain doesn't even resolve). OneSky itself seems to be killing its translation management service in favor of AI. We need to use something else.
I would suggest Weblate as a replacement. It's used by multiple large open source projects. Their own hosted instance has a plan for open-source projects which I think we would qualify under. It also seems to have tighter VCS integration, i.e. it can create pull requests by itself, if we decide we want that.