Fix #9386: compilers failing to compile with LTO by using variants instead of new + unique_ptr

With std::variant all memory can be figured out at compile time, so the compiler needs to keep track of fewer elements. It also saves out a unique_ptr and its memory management, over a slight impact for resolving a setting.

src/table/settings/win32_settings.ini

@@ -12,7 +12,7 @@
 #if defined(_WIN32) && !defined(DEDICATED)
 extern bool _window_maximize;
 
-static const SettingTable _win32_settings{
+static const SettingVariant _win32_settings[] = {
 [post-amble]
 };
 #endif /* _WIN32 */