function createPolyfillsLoaderScript(polyfills, polyfillsConfig, funcName = 'loadPolyfills') {
  return (
    `function ${funcName}() {` +
    loadScriptFunction +
    createPolyfillsLoader(polyfills, polyfillsConfig) +
    'return Promise.all(polyfills);\n' +
    '}'
  );
}
Creates a function that only loads polyfills, deferring entry loader to the caller
@param {import('@open-wc/building-utils/index-html/create-index-html').Polyfill[]} polyfills
@param {import('@open-wc/building-utils/index-html/create-index-html').PolyfillsConfig} polyfillsConfig