Really test against Symfony dev versions

Author: jmsche

.github/workflows/continuous-integration.yml

@@ -40,11 +40,11 @@ jobs:
           php-version: ${{ matrix.php-version }}
           extensions: zip
           coverage: pcov
+          tools: flex
 
-      - name: Install Symfony Flex
-        run: |
-          composer config --global --no-plugins allow-plugins.symfony/flex true
-          composer global require --no-progress --no-scripts --no-plugins symfony/flex
+      - name: Configure Composer minimum-stability for dev versions
+        if: contains(matrix.symfony-version, 'dev')
+        run: composer config minimum-stability dev
 
       - name: Install Composer dependencies
         uses: ramsey/composer-install@v3