ci: add PHP 8.5 to the test matrix

Author: oojacoboo

.github/workflows/continuous_integration.yml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       matrix:
         install-args: ['', '--prefer-lowest']
-        php-version: ['8.2', '8.3', '8.4']
+        php-version: ['8.2', '8.3', '8.4', '8.5']
       fail-fast: false
 
     steps: