Add PHP 8.1 to test action

Author: bilfeldt

.github/workflows/run-tests.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest]
-        php: [8.2]
+        php: [8.2, 8.1]
         laravel: [10.*]
         dependency-version: [prefer-stable]
         include: