Followup for SPI Flash

Marlin/src/gcode/gcode.cpp

         case 422: M422(); break;                                  // M422: Set Z Stepper automatic alignment position using probe
       #endif
 
-      #if BOTH(HAS_SPI_FLASH, SDSUPPORT)
+      #if ALL(HAS_SPI_FLASH, SDSUPPORT, MARLIN_DEV_MODE)
         case 993: M993(); break;                                  // M993: Backup SPI Flash to SD
         case 994: M994(); break;                                  // M994: Load a Backup from SD to SPI Flash
       #endif