Explicit version checks require application manifests on Win10, or an older version will be reported. Check for the toast notification history interface, which is only available on Win10+, and use that to determine if the Windows version is high enough to support notifications.
e.g.
SDL3/src/hidapi/libusb/hid.c:636:31: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
636 | static void start_event_thread()
GetTempPath2() is only available on Windows 11 and Windows 10 systems with full updates. We want to be compatible back to earlier versions of Windows and the only difference between the two calls is the behavior for processes running as SYSTEM, which we don't expect for SDL applications using notifications.