[doc] updated Doxygen version

Author: SimonRohou

.github/workflows/tests.yml

@@ -52,7 +52,7 @@ jobs:
         sudo apt-get -y install doxygen graphviz
 
         # Doxygen might need to be upgraded
-        git clone --depth 1 -b Release_1_13_0 https://github.com/doxygen/doxygen.git ; cd doxygen ; mkdir build ; cd build ; cmake .. ; sudo cmake --build . -j 4 --config Release --target install ; cd ../..
+        git clone --depth 1 -b Release_1_16_1 https://github.com/doxygen/doxygen.git ; cd doxygen ; mkdir build ; cd build ; cmake .. ; sudo cmake --build . -j 4 --config Release --target install ; cd ../..
 
         # For Python wrapping
         #pip install wheel

doc/manual/development/info_dev.rst

@@ -49,7 +49,7 @@ If you simply want to use the latest Codac release in Python, you can download t
       cd $HOME
       git clone https://github.com/doxygen/doxygen
       cd doxygen
-      git checkout Release_1_13_0 # 1.13.0, or any newer release
+      git checkout Release_1_16_1 # 1.16.1, or any newer release
       mkdir build ; cd build
       cmake -DCMAKE_INSTALL_PREFIX=$HOME/doxygen/build_install ..
       make ; make install