build: re-enabled builds on PHP 8.4

Author: thorsten

.github/workflows/build-php.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         operating-system: ['ubuntu-latest']
-        php-versions: ['8.2', '8.3']
+        php-versions: ['8.2', '8.3', '8.4']
     name: phpMyFAQ ${{ matrix.php-versions }} Test on ${{ matrix.operating-system }}
 
     steps: