users crate is unmaintained

[asomers]

cargo-audit reports that the users crate is unmaintained. Also, it suffers from an unaligned read bug. I suggest switching to Nix instead, which I think has all of the required functionality. Nix also dealt with the same unaligned read, IIRC, and fixed it.

Crate:     users
Version:   0.11.0
Warning:   unmaintained
Title:     `users` crate is unmaintained
Date:      2023-06-01
ID:        RUSTSEC-2023-0040
URL:       https://rustsec.org/advisories/RUSTSEC-2023-0040
Dependency tree:
users 0.11.0
└── rctl 0.2.1-alpha.0

Crate:     users
Version:   0.11.0
Warning:   unsound
Title:     Unaligned read of `*const *const c_char` pointer
Date:      2023-09-10
ID:        RUSTSEC-2023-0059
URL:       https://rustsec.org/advisories/RUSTSEC-2023-0059

warning: 2 allowed warnings found