Chain-rule sampling is incompatible with measurement on specifc wires

[Jooyuza]

Minimal example:

nmode=2
cutoff=3

cir = dq.QumodeCircuit(nmode, cutoff=cutoff, init_state='vac', backend='gaussian')
cir.s(wires=[0], r=1, theta=0)
cir.s(wires=[1], r=1, theta=0)
cir.bs(wires=[0,1])
cir()
cir.measure(wires=[1])

nmode=2
cutoff=3

cir = dq.QumodeCircuit(nmode, cutoff=cutoff, init_state='vac', backend='gaussian')
cir.s(wires=[0], r=1, theta=0)
cir.s(wires=[1], r=1, theta=0)
cir.bs(wires=[0,1])
cir()
cir.measure(wires=[1], with_prob=True)