Add PHP 8.5 to test workflow matrix

This commit adds PHP 8.5 to the GitHub Actions test workflow matrix to ensure the package is tested against the latest PHP version.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Spatie AI

.github/workflows/run-tests.yml

@@ -12,7 +12,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest]
-        php: [8.4, 8.3, 8.2]
+        php: [8.5, 8.4, 8.3, 8.2]
         laravel: ['11.*', '12.*']
         dependency-version: [prefer-lowest, prefer-stable]