Remove MRG_RandomStream?

[ferrine]

Description

there are random modules that we deprecated in pymc, not sure if we ever want them here
https://github.com/pymc-devs/pytensor/blob/main/pytensor/sandbox/rng_mrg.py
https://github.com/pymc-devs/pytensor/blob/main/pytensor/sandbox/multinomial.py

[ricardoV94]

Yes, we should remove those