Font Awesome 6 Update

## Feature Request
Officially Font Awesome 6 will be released in [February 2022](https://blog.fontawesome.com/font-awesome-6/), so I think maybe this issue could already be added to the next cycle.

The latest version `6.0.0-beta3` uses exactly the same licenses that are currently used in FA 5 (`CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License`) so no changes in the license should be expected, in fact, the [new docs](https://fontawesome.com/v6.0/docs/web/setup/upgrading/whats-changed) are almost finished and there is no mention of any change in this regard.

- Upgrade to FA 6: https://fontawesome.com/v6.0/docs/web/setup/upgrading/

Read the linked Font Awesome 6 upgrading guide and compare its requirements with the project's current Font Awesome integration. Confirm the dependency and asset changes needed, then verify that the project uses Font Awesome 6 and retains the stated CC BY 4.0, SIL OFL 1.1, and MIT licenses.

Written by the indexing model from the issue text.