ci: update actions/checkout to v5 and remove HHVM configuration

Author: roxblnfk

.github/workflows/ci.yml

@@ -16,27 +16,11 @@ jobs:
           - 8.2
           - 8.1
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
           coverage: xdebug
           ini-file: development
       - run: composer install
       - run: composer test:cc
-
-  PHPUnit-hhvm:
-    name: PHPUnit (HHVM)
-    runs-on: ubuntu-22.04
-    continue-on-error: true
-    steps:
-      - uses: actions/checkout@v4
-      - run: cp "$(which composer)" composer.phar && ./composer.phar self-update --2.2 # downgrade Composer for HHVM
-      - name: Run hhvm composer.phar install
-        uses: docker://hhvm/hhvm:3.30-lts-latest
-        with:
-          args: hhvm composer.phar install
-      - name: Run hhvm vendor/bin/phpunit
-        uses: docker://hhvm/hhvm:3.30-lts-latest
-        with:
-          args: hhvm vendor/bin/phpunit