Add PHP 8.4 to workflow matrices

Author: iv-craig

.github/workflows/phpstan.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: [8.3]
+        php: [8.3, 8.4]
 
     steps:
       - name: Checkout code

.github/workflows/tests.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: [8.1, 8.2, 8.3]
+        php: [8.1, 8.2, 8.3, 8.4]
 
     name: Tests on PHP ${{ matrix.php }} - ${{ matrix.stability }}