build: Force default libdir location for libhandy target on Windows to keep MinGW compatibility

5 jobs from mingw64 in 4 minutes and 31 seconds (queued for 14 seconds)
Status Job ID Name Coverage
  Build
passed #8412
librem5
build-debian-clang

00:02:26

passed #8410
librem5
build-debian-gcc

00:03:01

39.8%
passed #8411
librem5
build-debian-gcc-static

00:02:01

passed #8414
librem5
build-debian-package

00:01:57

passed #8413
librem5
build-fedora-gcc

00:02:54