build: Opt out from using mingw-w64's replacement printf(), etc.
The Windows code in dbus is careful to use Windows-specific equivalents of the Standard C features that are not implemented by msvcrt.dll, so we don't need to substitute a Standard C printf implementation.
This avoids compiler warnings/errors when gcc expects us to be using Microsoft printf syntax (
ms_printfattribute), but newer versions of mingw-w64 expect us to be using GNU or Standard C printf syntax (
gnu_printfattribute) as a result of
__USE_MINGW_ANSI_STDIObeing enabled by default if not otherwise specified.
Resolves: #380 (closed)
CI: Use current Debian stable release for mingw-w64 builds
Now that we have resolved the failure to build with newer mingw-w64, we don't need to hold these back to Debian 10 'buster' and can upgrade to the current stable release, Debian 11 'bullseye'.
CI: Make most gcc warnings fatal for CMake builds
This makes sure we notice problems early.