An atom that has 2 sigma and 2 pi bonds can either have a triple bond and a single bond or two double bonds. In either case, it is sp hybridized.
Put in another way, for an atom to have two pi bonds, it needs 2 unhybridized p orbitals. Since there are three p orbitals, only 1 p is available to hybridize with s.
In any case, it is not sp3 hybridized.