gnu/tests/chgrp/from.sh is now fixed

by #7039

Author: sylvestre

util/why-error.md

@@ -1,6 +1,5 @@
 This file documents why some tests are failing:
 
-* gnu/tests/chgrp/from.sh - https://github.com/uutils/coreutils/issues/7039
 * gnu/tests/cp/preserve-gid.sh
 * gnu/tests/csplit/csplit-suppress-matched.pl
 * gnu/tests/date/date-debug.sh