fix SDL build on Windows ARM64

Author: kambala-decapitator

conan_profiles/msvc-arm64

@@ -2,3 +2,7 @@ include(base/msvc)
 
 [settings]
 arch=armv8
+
+[conf]
+# workaround for https://github.com/libsdl-org/SDL/issues/13254
+sdl/*:tools.cmake.cmaketoolchain:extra_variables={'SDL_LIBC': 'ON'}