Implement VJP for `python_print`

[carmocca]

🚀 Feature

Motivation

Enable debugging

Pitch

import torch
import thunder
from thunder.core.prims import python_print

def fn(x):
    y = x + 2
    python_print(y)
    return y

x = torch.randn(2, requires_grad=True)
cfn = thunder.jit(fn)
y = cfn(x)

NotImplementedError: VJP for PrimIDs.PRINT is not implemented