Documentation in C++ classes gets mixed with PyROOT doc box

[etejedor]

The box that contains PyROOT documentation for a given class used to appear after the documentation that is written in the C++ file for that class. This is not the case anymore, for example:

https://root.cern.ch/doc/master/classTTree.html
https://root.cern.ch/doc/master/classTFile.html

Currently the first sentence of the C++ file docs appears first, after that there is the PyROOT box and finally the rest of the docs present in the C++ file.

[couet]

I am investigating why the Python panels are now coming first in the documentation. I think they came last just "by chance" before. Nothing indicates which \class TFile should be read first. Which by the way is something also a bit stange ie: twice the same \class ... I suspect Doxygen behavior is undefined in that case. I did not find anything mentionning the fact we can have the same \class twice... I am investigating ... no solution yet.

[couet]

I opened an issue on the doxygen repository asking what the behaviour should be when \class is defined twice.
doxygen/doxygen#8693

[etejedor]

This was fixed by #8971