CAMBRIDGE, Mass. — Time was when renting an apartment in one of this college town’s funky triple-deckers or two-family homes wouldn’t cost an arm and a leg. Now, renting in Cambridge can feel like that — something critics say is made tougher by short-term rental websites like Airbnb, through which property owners can make more money renting out apartments or homes by the night instead of a yearlong lease. The debate over services like Airbnb — often criticized for essentially turning apartments into hotel rooms, putting upward pressure on housing costs and driving out longer-term tenants who can’t afford rising rents — has raged for years in major cities.