[test] Set _LIBCPP_VERSION check in check-libcxx-version.cpp to include 170004.

This fixes test failures of libcxx-module-interface.swift and
libcxx-symbolic-module-interface.swift where the std module was split.
e.g building against a MacOS 14.4 SDK.

Author: rjmansfield

test/Interop/Cxx/stdlib/Inputs/check-libcxx-version.cpp

@@ -6,7 +6,7 @@ int main() {
   return 1;
 #endif
 
-#if _LIBCPP_VERSION >= 170006
+#if _LIBCPP_VERSION >= 170004
   return 0;
 #else
   return 1;