Remove redundant tool dependency installation step from CI workflow

The arduino/actions/libraried/compile-examples action's installation of the electroniccats:mbed package via Boards
Manager installs the platform's tools dependencies, so it's not necessary to do this separately.

Author: per1234

.github/workflows/compile-examples.yml

@@ -46,14 +46,6 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
-      
-      - name: Setup Python
-        uses: actions/setup-python@v1
-        with:
-          python-version: '3.x'
-      
-      - name: Install nrfutil
-        run: pip3 install adafruit-nrfutil
 
       # The source files are in a subfolder of the ArduinoCore-API repository, so it's not possible to clone it directly to the final destination in the core
       - name: Checkout ArduinoCore-API