use Composer 2.8 to install dependencies

Author: xabbuh

.github/workflows/ci.yaml

@@ -91,6 +91,7 @@ jobs:
                   coverage: none
                   extensions: mbstring, intl, pdo, pdo_sqlite, sqlite3
                   ini-values: date.timezone=UTC
+                  tools: composer:2.8
 
             - name: symfony/flex is required to install the correct symfony version
               if: ${{ matrix.symfony_version }}