Update dependency @fortawesome/fontawesome-free to v6.4.0

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
@fortawesome/fontawesome-free (source)	6.3.0 -> 6.4.0

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Release Notes

FortAwesome/Font-Awesome

### [`v6.4.0`](https://togithub.com/FortAwesome/Font-Awesome/releases/tag/6.4.0) [Compare Source](https://togithub.com/FortAwesome/Font-Awesome/compare/6.3.0...6.4.0) **Change log available at https://fontawesome.com/docs/changelog/**

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