ci: add 8.4

Author: yajra

.github/workflows/continuous-integration.yml

@@ -14,14 +14,14 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: [8.2, 8.3]
+        php: [8.2, 8.3, 8.4]
         stability: [prefer-stable]
 
     name: PHP ${{ matrix.php }} - ${{ matrix.stability }}
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2