Use modern API of arduino/compile-sketches CI action

The API of the arduino/compile-sketches GitHub Actions action has evolved since the time this repository's CI was set
up. Although backwards compatibility with the previous API was retained, its use is deprecated and results in
potentially confusing warnings.

Author: per1234

.github/workflows/compile-examples.yml

@@ -29,7 +29,9 @@ jobs:
         - source-path: ./
         - name: ArduinoECCX08
       # sketch paths to compile (recursive) for all boards
-      UNIVERSAL_SKETCH_PATHS: '"examples/SHA1" "examples/SHA256"'
+      UNIVERSAL_SKETCH_PATHS: |
+        - examples/SHA1
+        - examples/SHA256
       SKETCHES_REPORTS_PATH: sketches-reports
 
     strategy:
@@ -51,13 +53,15 @@ jobs:
               type: wifi101
             libraries: |
               - name: WiFi101
-            sketch-paths: '"examples/WiFiSSLClient"'
+            sketch-paths: |
+              - examples/WiFiSSLClient
           # GSM boards
           - board:
               type: gsm
             libraries: |
               - name: MKRGSM
-            sketch-paths: '"examples/MKRGSMSSLClient"'
+            sketch-paths: |
+              - examples/MKRGSMSSLClient
 
     steps:
       - name: Checkout
@@ -70,10 +74,11 @@ jobs:
           libraries: |
             ${{ env.UNIVERSAL_LIBRARIES }}
             ${{ matrix.libraries }}
-          sketch-paths: ${{ env.UNIVERSAL_SKETCH_PATHS }} ${{ matrix.sketch-paths }}
-          size-report-sketch: SHA256
-          enable-size-deltas-report: true
+          sketch-paths: |
+            ${{ env.UNIVERSAL_SKETCH_PATHS }}
+            ${{ matrix.sketch-paths }}
           verbose: true
+          enable-deltas-report: true
           sketches-report-path: ${{ env.SKETCHES_REPORTS_PATH }}
 
       - name: Save sketches report as artifact