use PHP8.3

Author: tdebatty

.github/workflows/php.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     container:
-      image: cylab/php:8.4
+      image: cylab/php:8.3
 
     steps:
     - uses: actions/checkout@v4

composer.json

@@ -10,7 +10,7 @@
     "require-dev": {
         "squizlabs/php_codesniffer": "^4.0",
         "slevomat/coding-standard": "^8.28",
-        "phpunit/phpunit": "^13.0"
+        "phpunit/phpunit": "^12.0"
     },
     "config": {
         "allow-plugins": {