build-export: Don't use generate-sizes

This is pretty inefficient in terms of download counts, and its not
cached. Lets store the data we need in the summary, which we need
to download anways, and which we cache.

app/xdg-app-builtins-build-export.c

@@ -365,8 +365,7 @@ xdg_app_builtin_build_export (int argc, char **argv, GCancellable *cancellable,
   if (!ostree_mutable_tree_ensure_dir (mtree, "files", &files_mtree, error))
     goto out;
 
-  modifier = ostree_repo_commit_modifier_new (OSTREE_REPO_COMMIT_MODIFIER_FLAGS_SKIP_XATTRS |
-                                              OSTREE_REPO_COMMIT_MODIFIER_FLAGS_GENERATE_SIZES,
+  modifier = ostree_repo_commit_modifier_new (OSTREE_REPO_COMMIT_MODIFIER_FLAGS_SKIP_XATTRS,
                                               (OstreeRepoCommitFilter)commit_filter, &commit_data, NULL);
 
   if (opt_runtime)