Feature request: make `randperm` stable

I am assuming that the following code should produce the exact same results in Julia v1.12 and v1.13:

```julia
using Random
using StableRNGs

rng = StableRNG(123)
randperm(rng, 9)
```

Am I missing something?

Start by reproducing the randperm(rng, 9) example with StableRNG on Julia v1.12 and v1.13, then inspect the randperm entry point and its version-specific behavior. Done means the same StableRNG seed produces identical permutations across both Julia versions, with tests covering the compatibility case.

Written by the indexing model from the issue text.