Improve and Cleanup Shutdown callbacks (#21060)

Co-authored-by: Dasky <32983009+daskygit@users.noreply.github.com>

layouts/community/numpad_5x6/bjohnson/keymap.c

@@ -44,10 +44,11 @@ bool led_update_user(led_t led_state) {
   return false;
 }
 
-void shutdown_user (void) {
+bool shutdown_user(bool jump_to_bootloader) {
   #ifdef RGBLIGHT_ENABLE
     rgblight_enable_noeeprom();
     rgblight_mode_noeeprom(RGBLIGHT_MODE_STATIC_LIGHT);
     rgblight_setrgb(RGB_RED);
   #endif // RGBLIGHT_ENABLE
+    return false;
 }