The border would previously get brighter after click, but then dim
instantly when the flash layer has fully faded out. The underlying issue
there is https://github.com/ppy/osu-framework/issues/5191, but
`ShearedButton` was placing the flashing layer incorrectly anyway, as
the intent was that it should also apply to the border.
Will still keep the override in `ClockBackedTestWorkingBeatmap` because
it still relies on a local track store and will fail the moment it uses
a non-virtual track.
Rather than fiddling around with the activation modes, this seems like a
much cleaner way to make things work.
Closes https://github.com/ppy/osu/issues/18277.