MFH: r527804
www/firefox: update to 74.0
Changes: https://www.mozilla.org/firefox/74.0/releasenotes/
PR: 244310
Security: 9f900456-0bfa-4da4-ad59-14b2933259a2
Approved by: ports-secteam blanket
Differential Revision: https://reviews.freebsd.org/D23646