Currently the following models give a NotImplementedError:

`
model = cp.Model()

vars = cp.intvar(0,10,shape=2)

model += ((vars[0] % 4) == vars[1])

model.solve(solver="pumpkin")
`

`
model = cp.Model()

vars = cp.intvar(0,10,shape=2)

model += ((vars[0] % 4) == vars[1])

model.solve(solver="pumpkin")
`

This is because we do not linearize constraints for pumpkin, but exponentiation or modulo division are also not natively supported in pumpkin.
I'm making a PR that linearizes the constraints and in the future this can maybe use the native constraints in pumpkin