diffutils: update 3.8 -> 3.9

NEWS

* Noteworthy changes in release 3.9 (2023-01-15) [stable]

** Bug fixes

  diff -c and -u no longer output incorrect timezones in headers
  on platforms like Solaris where struct tm lacks tm_gmtoff.
  [bug#51228 introduced in 3.4]

Drop patch as issue fixed upstream.

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit e5ec5de7)
Signed-off-by: Steve Sakoman <steve@sakoman.com>