Update actions/checkout to v4

Author: cmaglie

Diff for: .github/workflows/compile-examples.yml

@@ -198,11 +198,11 @@ jobs:
               
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       # 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
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           repository: arduino/ArduinoCore-API
           path: ArduinoCore-API