v4 artifact

Author: MATTYGILO

.github/workflows/build_boards.yml

@@ -74,7 +74,7 @@ jobs:
           chmod +x ../../scripts/assemble-unified-image-esp.sh
 
       - name: Archive Firmware
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: microlite-esp32-${{ matrix.board_type }}-firmware
           path: |