test_initgroups fails.

[TheJonny]

On commit f129095 the test test_initgroups failed. I ran cargo test as root.

# id
uid=0(root) gid=0(root) groups=0(root)
# uname -a
Linux charon 6.6.28-1-lts #1 SMP PREEMPT_DYNAMIC Wed, 17 Apr 2024 10:11:09 +0000 x86_64 GNU/Linux

failures:

---- test_unistd::test_initgroups stdout ----
thread 'test_unistd::test_initgroups' panicked at test/test_unistd.rs:322:5:
assertion `left == right` failed
  left: [Gid(0), Gid(123)]
 right: [Gid(123), Gid(0)]
stack backtrace:
   0: rust_begin_unwind
             at /rustc/25ef9e3d85d934b27d9dada2f9dd52b1dc63bb04/library/std/src/panicking.rs:647:5
   1: core::panicking::panic_fmt
             at /rustc/25ef9e3d85d934b27d9dada2f9dd52b1dc63bb04/library/core/src/panicking.rs:72:14
   2: core::panicking::assert_failed_inner
             at /rustc/25ef9e3d85d934b27d9dada2f9dd52b1dc63bb04/library/core/src/panicking.rs:342:17
   3: core::panicking::assert_failed
             at /rustc/25ef9e3d85d934b27d9dada2f9dd52b1dc63bb04/library/core/src/panicking.rs:297:5
   4: test::test_unistd::test_initgroups
             at ./test/test_unistd.rs:322:5
   5: test::test_unistd::test_initgroups::{{closure}}
             at ./test/test_unistd.rs:299:21
   6: core::ops::function::FnOnce::call_once
             at /rustc/25ef9e3d85d934b27d9dada2f9dd52b1dc63bb04/library/core/src/ops/function.rs:250:5
   7: core::ops::function::FnOnce::call_once
             at /rustc/25ef9e3d85d934b27d9dada2f9dd52b1dc63bb04/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.


failures:
    test_unistd::test_initgroups

test result: FAILED. 357 passed; 1 failed; 2 ignored; 0 measured; 0 filtered out; finished in 10.78s

I think there isn't a guarantee about the order of the group list.