Remove unsupported AVR board

Makefile

@@ -202,16 +202,11 @@ upload-rak4631:
 
 release: release-all
 
-release-all: console-site spiffs-image release-rnode release-tbeam release-tbeam_sx1262 release-lora32_v10 release-lora32_v20 release-lora32_v21 release-lora32_v10_extled release-lora32_v20_extled release-lora32_v21_extled release-lora32_v21_tcxo release-featheresp32 release-genericesp32 release-heltec32_v2 release-heltec32_v3 release-heltec32_v2_extled release-rnode_ng_20 release-rnode_ng_21 release-t3s3 release-hashes
+release-all: console-site spiffs-image release-tbeam release-tbeam_sx1262 release-lora32_v10 release-lora32_v20 release-lora32_v21 release-lora32_v10_extled release-lora32_v20_extled release-lora32_v21_extled release-lora32_v21_tcxo release-featheresp32 release-genericesp32 release-heltec32_v2 release-heltec32_v3 release-heltec32_v2_extled release-rnode_ng_20 release-rnode_ng_21 release-t3s3 release-hashes
 
 release-hashes:
 	python ./release_hashes.py > ./Release/release.json
 
-release-rnode:
-	arduino-cli compile --fqbn unsignedio:avr:rnode -e
-	cp build/unsignedio.avr.rnode/RNode_Firmware.ino.hex Release/rnode_firmware.hex
-	rm -r build
-
 release-tbeam:
 	arduino-cli compile --fqbn esp32:esp32:t-beam -e --build-property "build.partitions=no_ota" --build-property "upload.maximum_size=2097152" --build-property "compiler.cpp.extra_flags=\"-DBOARD_MODEL=0x33\""
 	cp ~/.arduino15/packages/esp32/hardware/esp32/$(ESP_IDF_VER)/tools/partitions/boot_app0.bin build/rnode_firmware_tbeam.boot_app0