Fix CI

Author: mathieucarbou

.github/workflows/ci.yml

@@ -104,6 +104,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install --upgrade platformio
+          pip install --upgrade intelhex
 
       - run: PLATFORMIO_SRC_DIR=examples/Client PIO_BOARD=${{ matrix.board }} pio run -e ${{ matrix.env }}
       - run: PLATFORMIO_SRC_DIR=examples/FetchWebsite PIO_BOARD=${{ matrix.board }} pio run -e ${{ matrix.env }}