ipv6 support

[clyso-dr]

We run a ipv6 only cluster and find following in the helm chart - https://github.com/Checkmk/checkmk_kube_agent/blob/2bfcf8ff0f0a2cd804464ce18ac8a0e985097e11/deploy/charts/checkmk/templates/cluster-collector-deploy.yaml#L49

We are already create a workaround for testing on our side with:

            {{- if .Values.clusterCollector.ipv6 }}
            - "--host=[::]"
            {{- else }}
            - "--host=0.0.0.0"
            {{- end }}

But now we are running into different trouble, so could it be that there is a general ipv6 support missing?

CRITICAL:	 2023-09-27 15:04:01,574 - Failed to send container metrics to cluster collector: Internal Server Error
Traceback (most recent call last):
  File "/usr/local/bin/checkmk-container-metrics-collector", line 8, in <module>
    sys.exit(main_container_metrics())
  File "/usr/local/lib/python3.10/site-packages/checkmk_kube_agent/send_metrics.py", line 466, in _main
    worker(session, cluster_collector_base_url, headers, verify)
  File "/usr/local/lib/python3.10/site-packages/checkmk_kube_agent/send_metrics.py", line 355, in container_metrics_worker
    _verify_and_log_cluster_collector_response(
  File "/usr/local/lib/python3.10/site-packages/checkmk_kube_agent/send_metrics.py", line 416, in _verify_and_log_cluster_collector_response
    cluster_collector_response.raise_for_status()
  File "/usr/local/lib/python3.10/site-packages/requests/models.py", line 960, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 500 Server Error: Internal Server Error for url: http://checkmk-cluster-collector.monitoring:8080/update_container_metrics

    solved_result = await solve_dependencies(
  File "/usr/local/lib/python3.10/site-packages/fastapi/dependencies/utils.py", line 527, in solve_dependencies
    solved = await call(**sub_values)
  File "/usr/local/lib/python3.10/site-packages/checkmk_kube_agent/api.py", line 158, in authenticate_post
    return authenticate(
  File "/usr/local/lib/python3.10/site-packages/checkmk_kube_agent/api.py", line 95, in authenticate
    token_review_response = session.post(
  File "/usr/local/lib/python3.10/site-packages/requests/sessions.py", line 577, in post
    return self.request('POST', url, data=data, json=json, **kwargs)
  File "/usr/local/lib/python3.10/site-packages/requests/sessions.py", line 515, in request
    prep = self.prepare_request(req)
  File "/usr/local/lib/python3.10/site-packages/requests/sessions.py", line 443, in prepare_request
    p.prepare(
  File "/usr/local/lib/python3.10/site-packages/requests/models.py", line 318, in prepare
    self.prepare_url(url, params)
  File "/usr/local/lib/python3.10/site-packages/requests/models.py", line 386, in prepare_url
    raise InvalidURL(*e.args)
requests.exceptions.InvalidURL: Failed to parse: https://2a01:4f8:d0:448e:ffff::1:443/apis/authentication.k8s.io/v1/tokenreviews
2a01:4f8:d0:4482:ffff::aa28:43728 - "GET /health HTTP/1.1" 200

PS: we will do a pull request to helm chart if the rest is also ipv6 ready :-)