Deprecation warning for assign() from ember/polyfills

[raido]

Example source of deprecation warning for assign() polyfill.

As this addon is included in default app blueprint, a brand new generated app starts off with deprecation warnings for Ember 4.x

ember-fetch/addon/utils/mung-options-for-fetch.ts

Line 1 in eaf18b6

import { assign } from '@ember/polyfills';