Run log_rotation integ test on Amazon Linux 2

Ubuntu started shipping a default logrotate configuration for cloud-init
log files, which clashes with the one coming from ParallelCluster.

Run this test on Amazon Linux 2 until the issue is fixed on the cookbook.

Signed-off-by: Jacopo De Amicis <jdamicis@amazon.it>

Author: jdeamicis

tests/integration-tests/configs/released.yaml

@@ -148,7 +148,7 @@ test-suites:
       dimensions:
         - regions: ["il-central-1"]
           instances: {{ common.INSTANCES_DEFAULT_X86 }}
-          oss: ["ubuntu2004"]
+          oss: ["alinux2"]
           schedulers: ["slurm"]
   monitoring:
     test_monitoring.py::test_monitoring: