[Test] Using Rocky8 AMI for testing 3.11.1 (#6596)

Co-authored-by: Himani Deshpande <himanidp@amazon.com>

Author: himani2411

tests/integration-tests/configs/released.yaml

@@ -198,7 +198,7 @@ test-suites:
       dimensions:
         - regions: ["ca-central-1"]
           instances: {{ common.INSTANCES_DEFAULT_X86 }}
-          oss: ["rocky9"]
+          oss: ["rocky8"]
           schedulers: ["slurm"]
     test_slurm.py::test_slurm_protected_mode:
       dimensions: