`warning: Mix.Config.import_config/1 is deprecated`

Getting these warnings on `main`: 

```sh
warning: Mix.Config.import_config/1 is deprecated. Use the Config module instead
  config/config.exs:30

warning: Mix.Config.config/2 is deprecated. Use the Config module instead
  config/test.exs:3
```

Similar to: https://github.com/dwyl/content/issues/13 ⏳  (top result on `Google` for this search!)
We should fix this on the next release. 🛠️ 