DEPRECATION WARNING #{} interpolation near operators

[sauloperez]

What we should change and why (this is tech debt)

The Rails 4 upgrade brought the following deprecation warning that likely prevents upcoming gem upgrades

web_1     | DEPRECATION WARNING on line 78 of /bundles/gems/foundation-rails-5.5.2.1/vendor/assets/stylesheets/foundation/components/_top-bar.scss:
web_1     | #{} interpolation near operators will be simplified in a future version of Sass.
web_1     | To preserve the current behavior, use quotes:
web_1     |                                                                                                                                                                                     
web_1     |   unquote("#{lower-bound($medium-range)}")

Context

This came up after the merge of #5158

Impact and timeline

This, apart from slowing down the dev env and cluttering the output, it blocks future upgrades.

[RachL]

We are now on rails 6, so closing.