touch: replace nix by rustix

[oech3]

split #11548
increased 136 bytes and added libc again... but reduces some cfg s and unwrap()s.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/date-locale-hour (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tty/tty-eof (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/printf/printf-surprise is now passing!