Musl: error[E0425]: cannot find function close_range in crate libc

[peppergrayxyz]

#3373 introduced close_range which is only available on glibc

thus causing errors when building with musl (and other libcs). e.g.:

• https://gitlab.gnome.org/GNOME/glycin/-/merge_requests/328
• Musl: error[E0425]: cannot find function close_range in crate libc containers/aardvark-dns#730

Please consider adding a fall-back

[tgross35]

close_range is not supported in musl, you need to use the syscall https://docs.rs/libc/0.2.189/x86_64-unknown-linux-musl/libc/constant.SYS_close_range.html.