🐛 Fix laser/fan sync (#24460)

Followup to #22690, 307dfb15

Marlin/src/lcd/menu/menu_item.h

 
   inline void on_fan_update() {
     thermalManager.set_fan_speed(MenuItemBase::itemIndex, editable.uint8);
-    TERN_(LASER_SYNCHRONOUS_M106_M107, planner.buffer_sync_block(BLOCK_FLAG_SYNC_FANS));
+    TERN_(LASER_SYNCHRONOUS_M106_M107, planner.buffer_sync_block(BLOCK_BIT_SYNC_FANS));
   }
 
   #if ENABLED(EXTRA_FAN_SPEED)

buildroot/tests/mega2560

         MANUAL_FEEDRATE '{ 50*60, 50*60, 4*60 }' \
         AXIS_RELATIVE_MODES '{ false, false, false }'
 opt_enable REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER SDSUPPORT EEPROM_SETTINGS EEPROM_BOOT_SILENT EEPROM_AUTO_INIT MEATPACK_ON_SERIAL_PORT_1 \
-           LASER_FEATURE LASER_SAFETY_TIMEOUT_MS LASER_COOLANT_FLOW_METER AIR_EVACUATION AIR_EVACUATION_PIN AIR_ASSIST AIR_ASSIST_PIN
-exec_test $1 $2 "MEGA2560 RAMPS | Laser Feature | Air Evacuation | Air Assist | Cooler | Flowmeter | 12864 LCD | meatpack | Laser Safety Timeout | M3 Power Sync | Trap Power Smoothing | SERIAL_PORT_2 " "$3"
+           LASER_FEATURE LASER_SAFETY_TIMEOUT_MS LASER_COOLANT_FLOW_METER AIR_EVACUATION AIR_EVACUATION_PIN AIR_ASSIST AIR_ASSIST_PIN LASER_SYNCHRONOUS_M106_M107
+exec_test $1 $2 "MEGA2560 RAMPS | Laser Options | 12864 | Meatpack | Fan Sync | SERIAL_PORT_2 " "$3"
 
 #
 # Test Laser features with 44780 LCD