panvk: Skip ZS setup if there is no depth/stencil attachment

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15382>

src/panfrost/vulkan/panvk_vX_pipeline.c

@@ -685,6 +685,9 @@ static void
 panvk_pipeline_builder_parse_zs(struct panvk_pipeline_builder *builder,
                                 struct panvk_pipeline *pipeline)
 {
+   if (!builder->use_depth_stencil_attachment)
+      return;
+
    pipeline->zs.z_test = builder->create_info.gfx->pDepthStencilState->depthTestEnable;
    pipeline->zs.z_write = builder->create_info.gfx->pDepthStencilState->depthWriteEnable;
    pipeline->zs.z_compare_func =