- remove obsoleted parameters
- return non-zero exit code when warnings are found. Doxygen has an
  option that set exit code to non-zero on warnings, available in
  Doxygen 1.9.0+, see [1] and [2].

1. https://github.com/doxygen/doxygen/issues/8023
2. https://www.doxygen.nl/manual/config.html

NO_CHANGELOG=doxygen config
NO_DOC=doxygen config
NO_TEST=doxygen config

Follows up #8194