Update workflow to use setup-php and improve Composer cache setup

.github/workflows/test.yml

@@ -20,17 +20,29 @@ jobs:
     - name: Validate composer.json and composer.lock
       run: composer validate --strict
 
-    - name: Cache Composer packages
+    # Docs: https://github.com/shivammathur/setup-php
+    - name: Setup PHP
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: '8.3'
+        extensions: mbstring, dom, fileinfo
+        coverage: xdebug
+
+    - name: Get composer cache directory
       id: composer-cache
+      run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+    - name: Cache composer dependencies
       uses: actions/cache@v3
       with:
-        path: vendor
-        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
-        restore-keys: |
-          ${{ runner.os }}-php-
-
-    - name: Install dependencies
-      run: composer install --prefer-dist --no-progress
+        path: ${{ steps.composer-cache.outputs.dir }}
+        # Use composer.json for key, if composer.lock is not committed.
+        # key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.json') }}
+        key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+        restore-keys: ${{ runner.os }}-composer-
+
+    - name: Install Composer dependencies
+      run: composer install --no-progress --prefer-dist --optimize-autoloader
 
     - name: Run test suite
       run: composer run-script test