Fix test extension github action

Author: dirx

.github/workflows/test-extension-compatibility.yml

@@ -111,7 +111,7 @@ jobs:
           restore-keys: ${{ runner.os }}-${{ matrix.php }}-composer-
       - name: Install dependencies
         run: |
-          composer update --prefer-dist --prefer-stable --no-interaction
+          composer update --prefer-dist --prefer-stable --no-interaction --ignore-platform-req=ext-rdkafka
       - name: Install dependencies for test-extension
         run: |
           composer update --prefer-dist --prefer-stable --no-interaction -d resources/test-extension