Add demo script execution under Valgrind in CI workflow

Included a step to execute a demo script with Valgrind, enabling thorough memory leak checks and origin tracking. This addition helps in improving the robustness of the code by identifying and addressing potential memory issues early in the development cycle.

.github/workflows/continuous-integration-pecl.yml

@@ -43,6 +43,18 @@ jobs:
           make
         continue-on-error: true
 
+      # Run the demo script
+      - name: Run demo script
+        run: |
+          # Running demo script under Valgrind
+          valgrind \
+            --leak-check=full \
+            --show-leak-kinds=all \
+            --track-origins=yes \
+            php -n \
+              -d extension=./ext-rayaop/modules/rayaop.so \
+              demo/05-pecl.php
+
       # Combined step for PHPUnit and Valgrind analysis
       - name: Run Tests with Valgrind
         if: success() || failure()