libwebp: Fix CVE-2023-1999

Add patch to fix CVE-2023-1999

Link: https://github.com/webmproject/libwebp/commit/a486d800b60d0af4cc0836bf7ed8f21e12974129



Signed-off-by: Nikhil R <nikhil.r@kpit.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
(cherry picked from commit 8f6fcbe2)
Signed-off-by: Steve Sakoman <steve@sakoman.com>