Update CI workflow to use current versions of PHP and only Symfony versions still under maintenance

Squash-merge of FriendsOfBehat#38

Squashed commit of the following:

commit 91a118c
Author: Matthias Pigulla <mp@webfactory.de>
Date:   Wed Dec 17 09:35:55 2025 +0100

    Update eligible versions of PHPSpec

commit d260a41
Author: Matthias Pigulla <mp@webfactory.de>
Date:   Wed Dec 17 09:29:15 2025 +0100

    Avoid using Flex

commit 58eb188
Author: Matthias Pigulla <mp@webfactory.de>
Date:   Wed Dec 17 09:20:16 2025 +0100

    Update current PHP and Symfony versions

commit b648d7b
Author: Christopher Georg <christopher.georg@sr-travel.de>
Date:   Sat Nov 8 08:40:43 2025 +0100

    ci: add tests for PHP > 8.3

commit 67adb9a
Author: Christopher Georg <christopher.georg@sr-travel.de>
Date:   Fri Nov 7 15:41:28 2025 +0100

    ci: add tests for PHP > 8.3

commit 3517e91
Author: Christopher Georg <christopher.georg@sr-travel.de>
Date:   Fri Nov 7 15:40:19 2025 +0100

    ci: add tests for PHP > 8.3

commit 4d051fa
Author: Christopher Georg <christopher.georg@sr-travel.de>
Date:   Fri Nov 7 15:39:17 2025 +0100

    ci: add tests for PHP > 8.3

commit eedfe24
Author: Christopher Georg <christopher.georg@sr-travel.de>
Date:   Fri Nov 7 15:36:47 2025 +0100

    ci: add tests for PHP > 8.3

Author: mpdude

.github/workflows/test.yaml

@@ -49,15 +49,10 @@ jobs:
                   restore-keys: |
                       composer-${{ runner.os }}-${{ matrix.php-version }}-${{ matrix.symfony-version }}-
 
-            # We currently cannot use Flex to control versions of Symfony and its components, since that would also impose constraints
-            # that cannot anymore be fulfilled by Goutte.
-            - name: Configure Symfony version
-              run: composer require --no-update "symfony/config:${{ matrix.symfony-version }}" "symfony/dependency-injection:${{ matrix.symfony-version }}"
-
             - name: Install dependencies with targeted Symfony version
               run: composer install --prefer-dist --no-progress
-              # env:
-              #     SYMFONY_REQUIRE: ${{ matrix.symfony-version }}
+              env:
+                  SYMFONY_REQUIRE: ${{ matrix.symfony-version }}
 
             - name: PHPSpec
               run: vendor/bin/phpspec run -f pretty