Nans in JAX multinomial dispatch

### Description

PyMC tests are failing: https://github.com/pymc-devs/pymc/pull/7740

Reproducible example:
```python
import pytensor.tensor as pt

p = pt.eye(3)
rv = pt.random.multinomial(n=5, p=p)
rv.eval(mode="JAX")
# Array([[ 5., nan, nan],
#        [ 0.,  5.,  0.],
#        [ 0.,  0.,  5.]], dtype=float64)
```

I guess it could be a problem with binomial with p=0?

CC @educhesne 