[PRQ#41839] Deletion Request for firefox56

[notify]

FabioLolix [1] filed a deletion request for firefox56 [2]:

Reported to fail build twice in 2020 and not fixed, still fail,
ancient firefox version

[1] https://aur.archlinux.org/account/FabioLolix/
[2] https://aur.archlinux.org/pkgbase/firefox56/