Shouldn't `NodeBuilder::set_entropy_seed_bytes` just take a `[u8; 64]`

[TheBlueMatt]

It builds one internally anyway and requires the bytes be 64 long, why not avoid the vec?

[tnull]

Yes, I think this was a result of keeping the Uniffi and non-Uniffi APIs as close as possible (note we don't have separate docs for Uniffi). As they have diverged a bit by now anyways, I guess we could probably revert to take [u8; 64].

[tnull]

Now opened #493