**Apache Airflow version**: 2.0.1


**Kubernetes version (if you are using kubernetes)** (use `kubectl version`): 1.20.5

**Environment**:

- **Cloud provider or hardware configuration**: Azure AKS

**What happened**:

When task or dag name is defined with a non ascii character, pod creations fails with a kubernetes.client.rest.ApiException: (422)
(task maintains scheduled status)
this is because the hostname defined for the pod is based on dag and task name...

**What you expected to happen**:

Create the pod and run the task

**How to reproduce it**:
Run a task with name "campaña" on K8s executor,

Error log
```
{"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"Pod \"dagnamecampaña.0fb696e661e347968216df454b41b56f\" is invalid: metadata.name: Invalid value: \"dagnamecampaña.0fb696e661e347968216df454b41b56f\": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0
-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')","reason":"Invalid"
```



tests/executors/test_kubernetes_executor.py
pod_id = "my-pod-1"
        namespace = "my-namespace-3"
        mock_delete_namespace = mock.MagicMock()
        mock_kube_client.return_value.delete_namespaced_pod = mock_delete_namespace
        
        mock_kube_client.return_value.delete_namespaced_pod.side_effect = ApiException(status=404)
        kube_executor = KubernetesExecutor()
        kube_executor.job_id = "test-job-id"
        kube_executor.start()
        kube_executor.kube_scheduler.delete_pod(pod_id, namespace)
        mock_delete_namespace.assert_called_with(pod_id, namespace, body=mock_client.V1DeleteOptions())
class TestKubernetesExecutor(unittest.TestCase):
    """
    Tests if an ApiException from the Kube Client will cause the task to
    be rescheduled.
    """
    def setUp(self) -> None: