Dockerfile: update Doxygen version to 1.16.1

Update Doxygen to latest released version as it has a fix for a regression
observed in alphabetical sorting of groups which is impacting us.

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

Author: kartben

Dockerfile.base

@@ -17,7 +17,7 @@ ARG KITWARE_NINJA_VERSION=1.11.1.g95dee.kitware.jobserver-1
 ENV KITWARE_NINJA_VERSION=$KITWARE_NINJA_VERSION
 ARG CCACHE_VERSION=4.9.1
 ENV CCACHE_VERSION=$CCACHE_VERSION
-ARG DOXYGEN_VERSION=1.15.0
+ARG DOXYGEN_VERSION=1.16.1
 ENV DOXYGEN_VERSION=$DOXYGEN_VERSION
 ARG RENODE_VERSION=1.16.0
 ENV RENODE_VERSION=$RENODE_VERSION