Bump bifunctors upper bound (fpco/stackage#968)
Bump bifunctors upper bound (fpco/stackage#968)

mrkkrp/stack,Fuuzetsu/stack,achernyak/stack,deech/stack,AndrewRademacher/stack,martin-kolinek/stack,Blaisorblade/stack,anton-dessiatov/stack,Heather/stack,AndreasPK/stack,deech/stack,Blaisorblade/stack,achernyak/stack,juhp/stack,AndreasPK/stack,phadej/stack,luigy/stack,sjakobi/stack,phadej/stack,martin-kolinek/stack,MichielDerhaeg/stack,harendra-kumar/stack,mrkkrp/stack,anton-dessiatov/stack,MichielDerhaeg/stack,AndrewRademacher/stack,Fuuzetsu/stack,sjakobi/stack,narrative/stack,harendra-kumar/stack,luigy/stack,narrative/stack,juhp/stack,Heather/stack