[skip-ci] put back the ML tutorials.

Author: couet

documentation/doxygen/Doxyfile

@@ -1081,7 +1081,6 @@ EXCLUDE_PATTERNS       = */G__* \
                          */gui/qt5webdisplay/* \
                          */gui/qt6webdisplay/* \
                          */tutorials/visualisation/webgui/qt5web/* \
-                         */tutorials/machine_learning/* \
                          */math/mathcore/src/CDT*
 
 # The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names