Bring back the 3x3 filter for PCF shadows
Bring back the 3x3 filter for PCF shadows

The same can be achieved with VSM + blur=3 however, this is noticeably
slower. Also when using transparent shadows, VSM needs a much larger
blur to iron out the dithering pattern.

Fixes #5048, #5039
google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament