Seeing that this port has no maintainer, no dependencies and no apparent use case, I would argue for it to be removed.
A commit references this bug: Author: tobik Date: Sun Mar 11 17:35:52 UTC 2018 New revision: 464187 URL: https://svnweb.freebsd.org/changeset/ports/464187 Log: www/fira-webfont: Deprecate PR: 223845 Submitted by: marcel@herrbischoff.com Changes: head/www/fira-webfont/Makefile