ci: update min PHP version to 8.1

Author: tcarrio

.github/workflows/pullrequest.yml

@@ -20,7 +20,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ubuntu-latest]
-        php-version: ['8.0', '8.1', '8.2']
+        php-version: ['8.1', '8.2', '8.3']
 
     steps:
       - uses: actions/checkout@v4