feat(wokwi-test): add caching for PlatformIO to improve workflow efficiency

Author: JakubAndrysek

.github/workflows/wokwi-test.yml

@@ -70,6 +70,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Cache PlatformIO
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.platformio
+          key: ${{ runner.os }}-platformio-${{ hashFiles('**/platformio.ini') }}
+          restore-keys: |
+            ${{ runner.os }}-platformio-
+
       - name: Install PlatformIO
         run: |
           python -m pip install --upgrade pip