AMD GPUs do not appear to produce consistent results with other GPUs when using textureGather in the Metal backend. Disabling for now to ensure correct function of outline rendering.
This may require an additional sub-pixel offset in the texture sampling calls, to achieve correct behaviour.
Authored by Apple: Michael Parkin-White
Ref T103412
Ref T96261
Reviewed By: fclem
Maniphest Tasks: T103412, T96261
Differential Revision: https://developer.blender.org/D16934
cd2926fb05