This should be ignored on non-compute stages but AGX changes 3D shaders
to compute without setting the workgroup size and blows up if it claims
variable workgroups. The safest thing is to only set it from
spirv_to_nir for stages that actually have workgroups.
Fixes: 6d9f563960 ("spirv: Assume variable workgroup size unless it's set")
LoLed-by: Alyssa Rosenzweig <alyssa.rosenzweig@intel.com>
Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38555>