Closes https://github.com/ppy/osu/issues/28209.
Yes this means that such scores will have a zero total score without
mods in DB and thus might up getting their total recalculated to zero
when we try a mod multiplier rebalance (unless we skip scores with zero
completely I suppose). I also don't really care about that right now.
Rather than creating a "corrupt" realm file in such cases, the game will
now refuse to start. This behaviour is usually what we want. In most
cases a second click on the game will start it successfully (the
previous instance's file handles are still doing stuff, or windows
defender is being silly).
Closes https://github.com/ppy/osu/issues/28018.