Remove Twig 2.x from CI matrix

Twig 2.x is EOL and all versions are blocked by Composer security
advisories, making the test matrix impossible to run. Simplified the
workflow to use modern Symfony Flex configuration.

Author: Rafikooo

.github/workflows/build.yml

@@ -13,16 +13,13 @@ on:
 jobs:
     tests:
         runs-on: ubuntu-latest
-        name: "PHP ${{ matrix.php }}, Symfony ${{ matrix.symfony }}, Twig ${{ matrix.twig }}"
+        name: "PHP ${{ matrix.php }}, Symfony ${{ matrix.symfony }}"
         strategy:
             fail-fast: false
             matrix:
                 php: ["8.1", "8.2", "8.3"]
                 symfony: ["^5.4", "^6.4", "^7.0"]
-                twig: ["^2.12", "^3.3"]
                 exclude:
-                    - twig: "^2.12"
-                      symfony: "^7.0"
                     - php: "8.1"
                       symfony: "^7.0"
 
@@ -36,22 +33,15 @@ jobs:
                 with:
                     php-version: "${{ matrix.php }}"
                     coverage: none
+                    tools: 'composer:v2, flex'
 
             -
                 name: Restrict Symfony version
                 if: matrix.symfony != ''
                 run: |
-                    composer global config --no-plugins allow-plugins.symfony/flex true
-                    composer global require --no-progress --no-scripts --no-plugins "symfony/flex:^1.10"
                     composer config extra.symfony.require "${{ matrix.symfony }}"
                     (cd src/Component && composer config extra.symfony.require "${{ matrix.symfony }}")
 
-            -
-                name: Restrict Twig version
-                if: matrix.twig != ''
-                run: |
-                    composer require "twig/twig:${{ matrix.twig }}" --no-update --no-scripts
-
             -
                 name: Install dependencies
                 run: |