🎨 Power-off tone followup (#22222)

Marlin/src/feature/power.cpp

 #include "../module/stepper/indirection.h"
 #include "../MarlinCore.h"
 
+#if ENABLED(PS_OFF_SOUND)
+  #include "../libs/buzzer.h"
+#endif
+
 #if defined(PSU_POWERUP_GCODE) || defined(PSU_POWEROFF_GCODE)
   #include "../gcode/gcode.h"
 #endif
     #ifdef PSU_POWEROFF_GCODE
       GcodeSuite::process_subcommands_now_P(PSTR(PSU_POWEROFF_GCODE));
     #endif
+
+    #if ENABLED(PS_OFF_SOUND)
+      BUZZ(1000, 659);
+    #endif
+
     PSU_PIN_OFF();
   }
 }

Marlin/src/gcode/control/M80_M81.cpp

     #endif
   #endif
 
-  #if ENABLED(PS_OFF_SOUND)
-    BUZZ(1000, 659);
-  #endif
-
   safe_delay(1000); // Wait 1 second before switching off
 
   #if HAS_SUICIDE