Add _winapi.GetTickCount64

Author: srittau

stdlib/_winapi.pyi

@@ -312,3 +312,6 @@ if sys.platform == "win32":
     if sys.version_info >= (3, 12):
         def CopyFile2(existing_file_name: str, new_file_name: str, flags: int, progress_routine: int | None = None) -> int: ...
         def NeedCurrentDirectoryForExePath(exe_name: str, /) -> bool: ...
+
+    if sys.version_info >= (3, 15):
+        def GetTickCount64() -> int: ...