This intentionally removes shear specification from root level of
`BeatmapTitleWedge` since shearing is moved one level higher (see fill
flow containing `BeatmapTitleWedge` in `SongSelect`).
Keep masking back in `Content`, since the scaling animation is happening
on `Content` instead of `this`. This doesn't regress the intended
behaviour in this PR (which is to just to make the button class itself
sheared instead of its content).