Enable core dumps in GitHub workflow

This commit adds a step to the GitHub workflow to enable core dumps, useful for debugging. Additionally, it modifies the command for running the demo to use customized PHP configurations, including a limit on memory usage and enabling memory leak reports.

.github/workflows/build.yml

@@ -23,6 +23,11 @@ jobs:
           php-version: ${{ matrix.php-version }}
           extensions: mbstring, intl
 
+      - name: Enable core dumps
+        run: |
+          ulimit -c unlimited
+          echo '/tmp/core-%e.%p' | sudo tee /proc/sys/kernel/core_pattern
+
       - name: Install build tools
         run: sudo apt-get update && sudo apt-get install -y autoconf automake libtool bison re2c
 
@@ -38,4 +43,4 @@ jobs:
       - name: Run demo
         run: |
           php -d extension=./modules/rayaop.so -i | grep rayaop
-          php -d extension=./modules/rayaop.so rayaop.php
+          php -d extension=./modules/rayaop.so -d memory_limit=128M -d report_memleaks=1 rayaop.php