Saves having this defined in 20+ places. If we ever make any changes to
shear, it's 100% going to need to be applied to every usage (there will
never be a case of multiple different shears in the game).
Also fixes a mismatching definition in `ShearedNub`.
Closes https://github.com/ppy/osu/issues/27549.
I'm not entirely sure why the old solution failed exactly, but also
think it's unimportant because I think past me was an idiot and was
playing stupid games with the juggling of indices between two callbacks
with no ordering guarantees and expecting not to win stupid prizes.
I'm not sure this requires any follow-up reconsiderations of that entire
text flow API, but if opinions differ, I'll re-examine.