Rebuild the language picker using native elements

Quote from the Accessibility audit:

There is a dropdown component in the footer used to change the language of the site. Using this selector is not comfortable for screen reader, motor impaired and keyboard users as it does not adhere to usage principles established by the vanilla component. It is not searchable and not usable using the arrow keys on the keyboard immediately upon activation. The component also does not explain to the user that it is a select box, and it does not announce its state change from closed to open using aria-expanded. Consider entirely replacing this with the vanilla component instead of trying to add this functionality to your custom solution.