Fix duplicate board IDs (#14310)

Marlin/Makefile

 # Einsy Retro
 else ifeq ($(HARDWARE_MOTHERBOARD),305)
 # Elefu Ra Board (v3)
-else ifeq ($(HARDWARE_MOTHERBOARD),21)
+else ifeq ($(HARDWARE_MOTHERBOARD),23)
 # Leapfrog
 else ifeq ($(HARDWARE_MOTHERBOARD),999)
 # Mega controller

Marlin/src/core/boards.h

 #define BOARD_MINIRAMBO_10A     303   // Mini-Rambo 1.0a
 #define BOARD_EINSY_RAMBO       304   // Einsy Rambo
 #define BOARD_EINSY_RETRO       305   // Einsy Retro
-#define BOARD_ELEFU_3           21    // Elefu Ra Board (v3)
+#define BOARD_ELEFU_3           23    // Elefu Ra Board (v3)
 #define BOARD_LEAPFROG          999   // Leapfrog
 #define BOARD_MEGACONTROLLER    310   // Mega controller
 #define BOARD_SCOOVO_X9H        321   // abee Scoovo X9H
 #define BOARD_MORPHEUS         1806   // STM32F103C8/STM32F103CB Libmaple based stm32f1 controller
 #define BOARD_MKS_ROBIN        1808   // MKS Robin / STM32F103ZET6
 #define BOARD_BIGTREE_SKR_MINI_V1_1 1814 // STM32F103RC
-#define BOARD_JGAURORA_A5S_A1  1810   // JGAurora A5S A1 / STM32F103ZET6
+#define BOARD_JGAURORA_A5S_A1  1820   // JGAurora A5S A1 / STM32F103ZET6
 
 //
 // STM32 ARM Cortex-M4F

buildroot/share/PlatformIO/scripts/jgaurora_a5s_a1_with_bootloader.py

 Import("env")
 
 # Relocate firmware from 0x08000000 to 0x0800A000
-env['CPPDEFINES'].remove(("VECT_TAB_ADDR", "0x8000000")) 
+env['CPPDEFINES'].remove(("VECT_TAB_ADDR", "0x8000000"))
 #alternatively, for STSTM <=5.1.0 use line below
 #env['CPPDEFINES'].remove(("VECT_TAB_ADDR", 134217728))
 env['CPPDEFINES'].append(("VECT_TAB_ADDR", "0x0800A000"))
 
 #append ${PROGNAME}.bin firmware after bootloader and save it as 'jgaurora_firmware.bin'
 def addboot(source,target,env):
-	import os	
+	import os
 
 	firmware = open(target[0].path, "rb")
 	lengthfirmware = os.path.getsize(target[0].path)
 	while position < lengthfirmware:
 		byte = firmware.read(1)
 		firmwareimage.write(byte)
-		position += 1	
+		position += 1
 	bootloader.close()
 	firmware.close()
 	firmwareimage.close()
 	if os.path.exists(firmware_without_bootloader_dir):
 		os.remove(firmware_without_bootloader_dir)
 	os.rename(target[0].path, firmware_without_bootloader_dir)
-	#os.rename(target[0].dir.path+'/firmware_with_bootloader.bin', target[0].dir.path+'/firmware.bin') 
+	#os.rename(target[0].dir.path+'/firmware_with_bootloader.bin', target[0].dir.path+'/firmware.bin')
 
 env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", addboot);