Complete changes of 5e7b08f9ea (Correct wxDC::GetContentScaleFactor()
documentation, 2023-04-13) to add the information about the version in
which the behaviour of this function changed, as it was already done in
the version of this commit cherry picked to 3.2 branch, i.e. 8094ed5795
(Correct wxDC::GetContentScaleFactor() documentation, 2023-04-13).
Closes#23748.