brotli,libpng,libjpeg,libwebp,x265,libxml2,xxhash,spirv-tools: disable executable

[Andarwinux]

There should be a small speedup of the build. But for future LTO builds, this is a huge speedup and eventually we could get a full ThinLTO build in 60 minutes. (If ffmpeg.exe is disabled and mpv is dynamically linked, it will be reduced to 50 minutes)