grep: upgrade 3.9 -> 3.10

This is to announce grep-3.10, a stable release,
fixing a bug with -P and \d. TL;DR, grep-3.9 would do this:

  $ LC_ALL=en_US.UTF-8 grep -P '\d' <<< ٠١٢٣٤٥٦٧٨٩
  ٠١٢٣٤٥٦٧٨٩

It should print nothing, like it has always done.
For more detail, see https://lists.gnu.org/r/bug-grep/2023-03/msg00005.html



Thanks to Paul Eggert for catching the \D variant and to Bruno Haible
for assiduously tending gnulib and for testing grep on so many
different systems.

There have been 12 commits by 2 people in the 17 days since 3.9.

Signed-off-by: Denys Dmytriyenko <denis@denix.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>