RafDecoder::isCompressed(): adjust bpp cutoff threshold.
RafDecoder::isCompressed(): adjust bpp cutoff threshold.

Not ideal. Not sure what is the proper way.
At least no RPU samples break.

See https://redmine.darktable.org/issues/11868

darktable-org/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed