Installing the cores used for testing in the workflow.

Author: CreatingNull

.github/workflows/run-tests.yaml

@@ -50,7 +50,9 @@ jobs:
 
       - name: Setup Arduino CLI
         shell: bash
-        run: curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh -s 0.21.1
+        run: |
+          curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh -s 0.21.1
+          bin/arduino-cli core install arduino:avr
 
       - name: Put tools on path
         shell: bash