Pass -Werror=dev
in the CI, Guix and the dev-mode
preset.
https://cmake.org/cmake/help/latest/manual/cmake.1.html#cmdoption-cmake-Werror:
Make developer warnings errors. Make warnings that are meant for the author of the CMakeLists.txt files errors. By default this will also turn on deprecated warnings as errors.
Pulled out of #32865.