A Brazilian Harvard Law School professor who pleaded guilty last month to illegally firing an air rifle outside a Boston-area synagogue — and told police he was “hunting rats” — has agreed to leave the US following his arrest by Immigration and Customs Enforcement this week. Carlos Portugal Gouvea, 43, copped Nov. 13 to a single charge of illegal use of the air rifle in connection with the Oct. 2 incident outside of Brookline’s Temple Beth Zion, which took place on Yom Kippur, the holiest day in Judaism. The scholar was arrested by ICE Boston Enforcement and Removal Operations (ERO)...