Update stability option to prefer-stable in run-tests.yml

Author: cyrillkalita

.github/workflows/run-tests.yml

@@ -19,7 +19,7 @@ jobs:
         os: [ubuntu-latest, windows-latest]
         php: [8.4, 8.3, 8.2]
         laravel: [11.*]
-        stability: [prefer-lowest, prefer-stable]
+        stability: [prefer-stable]
         include:
           - laravel: 11.*
             testbench: 9.*