zink: flag the gfx pipeline dirty and unset pipeline shader module on shader change

there's no need to leave this until the module updating when the info
is known much earlier

Reviewed-by: Hoe Hao Cheng <haochengho12907@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12428>

src/gallium/drivers/zink/zink_program.c

@@ -881,8 +881,12 @@ bind_stage(struct zink_context *ctx, enum pipe_shader_type stage,
       ctx->compute_stage = shader;
       if (shader)
          zink_select_launch_grid(ctx);
-   } else
+   } else {
       ctx->gfx_stages[stage] = shader;
+      ctx->gfx_pipeline_state.combined_dirty = true;
+      if (!shader)
+         ctx->gfx_pipeline_state.modules[stage] = VK_NULL_HANDLE;
+   }
    ctx->dirty_shader_stages |= 1 << stage;
    if (shader && shader->nir->info.num_inlinable_uniforms)
       ctx->shader_has_inlinable_uniforms_mask |= 1 << stage;