test/utilities: adopt newly revamped `setup()`

test/lib/utilities.bats

@@ -1,10 +1,9 @@
-#!/usr/bin/env bats
+# shellcheck shell=bats
 
-load ../test_helper
-load ../test_helper_libs
+load "${MAIN_BASH_IT_DIR?}/test/test_helper.bash"
 
-function local_setup {
-  setup_test_fixture
+function local_setup_file() {
+  setup_libs "helpers"
 }
 
 @test "_bash-it-component-item-is-enabled() - for a disabled item" {