Update C++ standard and header in test function

Updated the C++ standard version in the test configuration and changed the included header from RandX.hpp to RandX_Cpp17.hpp.

Author: luadebug

packages/r/randx/xmake.lua

@@ -23,11 +23,11 @@ package("randx")
 
     on_test(function (package)
         assert(package:check_cxxsnippets({test = [[
-            #include <RandX.hpp>
+            #include <RandX_Cpp17.hpp>
             #include <cstdint>
             static void test() {
                 std::uint64_t v = RandX::RandInt<std::uint64_t>(0, 1000);
                 (void)v;
             }
-        ]]}, {configs = {languages = "c++23"}}))
+        ]]}, {configs = {languages = "c++17"}}))
     end)