nir/opt_shrink_vectors: Remove shrinking of store intrinsics data source

This is done via nir_opt_shrink_stores.

Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14480>

src/intel/compiler/brw_nir.c

@@ -553,7 +553,8 @@ brw_nir_optimize(nir_shader *nir, const struct brw_compiler *compiler,
       if (is_scalar) {
          OPT(nir_lower_alu_to_scalar, NULL, NULL);
       } else {
-         OPT(nir_opt_shrink_vectors, true);
+         OPT(nir_opt_shrink_stores, true);
+         OPT(nir_opt_shrink_vectors);
       }
 
       OPT(nir_copy_prop);