Review CI process to build doc (use image created during hysop CI, add meson...

Review CI process to build doc (use image created during hysop CI, add meson config ...) - Fix target deps (apidoc and sphinx)

meson.build

@@ -109,6 +109,7 @@ sphinx_docs = custom_target(
   command : [
     sphinx_build, '-w', 'sphinx.log', '-b', 'html', meson.project_source_root() , 'html'
   ],
-  depend_files : files('conf.py.in', 'index.rst', 'apidoc/modules.rst'),
+  depend_files : files('conf.py.in', 'index.rst'),
+  depends: apidoc,
   build_by_default : true
 )