Revert "fixed CI pipeline error with previous modernized additions"

This reverts commit 727bcf2.

Author: neil-pack

.github/workflows/ci.yml

@@ -9,7 +9,6 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    container: php:${{ matrix.php-version }}-cli
 
     strategy:
       fail-fast: false
@@ -22,24 +21,12 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v4
 
-    - name: Install system dependencies and PHP extensions
-      run: |
-        apt-get update
-        apt-get install -y git unzip libzip-dev libxml2-dev
-        docker-php-ext-install xml zip
-        if [ "${{ matrix.php-version }}" = "8.3" ]; then
-          pecl install xdebug
-          docker-php-ext-enable xdebug
-        fi
-        php -v
-        php -m
-
-    - name: Install Composer
-      run: |
-        php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
-        php composer-setup.php --install-dir=/usr/local/bin --filename=composer
-        rm composer-setup.php
-        composer --version
+    - name: Setup PHP
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: ${{ matrix.php-version }}
+        extensions: mbstring, xml, ctype, json
+        coverage: xdebug
 
     - name: Validate composer.json and composer.lock
       run: composer validate --strict