Fix MSVC runtime library conflict warning

Add /NODEFAULTLIB:LIBCMT linker flag to resolve LNK4098 warning
when building with MSVC. This excludes the static runtime library
that conflicts with Crystal's dynamic runtime (/MD).

Author: kojix2

src/uing/lib_ui/lib_ui.cr

@@ -11,6 +11,8 @@ module UIng
     @[Link("Windowscodecs")]
     @[Link("Uuid")]
     @[Link("Winmm")]
+    # Exclude LIBCMT to avoid conflicts with Crystal's MSVC runtime (/MD).
+    @[Link(ldflags: "/NODEFAULTLIB:LIBCMT")]
     # @[Link(ldflags: "/SUBSYSTEM:WINDOWS")]
     {% if flag?(:debug) %}
       @[Link(ldflags: "/DEBUG")]