Remove deprecated warn messages when running npm install

[Tubaleviao]

When we run npm install or npm i for the first time in this project, we get a few deprecated warns in the console, like so:

[YasharF]

Those warnings are because of the transition of Sass to its new version in the ecosystem and they don't have a functionality impact at this point. Until Bootstrap and other parties come up with a new version of their packages that support the latest version of Sass, the options are either to downgrade sass to a version before the devs added the warning messages (which may cause other deprecation messages) or consider it a known issue and wait for the 3rd parties to finish their upgrades:
Bootstrap: twbs/bootstrap#40962
FontAwesome: FortAwesome/Font-Awesome#19167