don't enable __USE_MINGW_ANSI_STDIO for UCRT builds

As seen in !3101 (comment 364630) with UCRT we no longer need the mingw hacks for the printf formats. This is also true with clang-cl and cl.exe builds.

This ensures more compatibility between the mingw-w64 builds and MSVC builds.

Draft: needs !3170 (merged) first