It was added in c9f38f7bb6, which
specified 2021 in another place (and was committed in October of 2020
anyway). Update the year so that it doesn't get culled prematurely.
In theory this seemed like a good idea (and an optimisation in some
cases, due to lower fill rate), but in practice this leads to weird edge
cases.
This aims to do away with the operations on external drawables by
applying a dim to the area behind the `LoadingLayer` when required.
I went over each usage and ensured they look as good or better than
previously.
The specific bad usage here was the restoration of the colour on dispose
(if the `LoadingLayer` was disposed in a still-visible state).
I'm aware that the `BeatmapListingOverlay` will now dim completely during
load. I think this is fine for the time being.