To the OP just as an FYI - our public HS offers through Latin V (honors, IB and/or AP) and 3 years of Greek (Greek is in O period and taken by very few students). So yours is not the only HS to offer this.
I would also be surprised if Boston Latin didn’t offer those courses - back in the day my college roommate who attended there had taken 6 years of Latin but I don’t know about Greek.