Currently the KubernetesPodOperator `env_vars` will be printed
on the task logs if there is any templating error (like an
`UndefinedError`, `TemplateSyntaxError` or `KeyError`)

```
[2023-01-16, 23:03:17 UTC] {abstractoperator.py:592} ERROR - Exception rendering Jinja template for task 'dry_run_demo', field 'env_vars'. Template: [{'name': 'password', 'value': 'secretpassword', 'value_from': None}, {'name': 'VAR2', 'value': '{{ var.value.nonexisting}}', 'value_from': None}]
Traceback (most recent call last):
  File "/Users/rubelagu/.pyenv/versions/3.10.7/envs/venv-airflow-250/lib/python3.10/site-packages/airflow/models/abstractoperator.py", line 585, in _do_render_template_fields
    rendered_content = self.render_template(
  File "/Users/rubelagu/.pyenv/versions/3.10.7/envs/venv-airflow-250/lib/python3.10/site-packages/airflow/models/abstractoperator.py", line 657, in render_template
    return [self.render_template(element, context, jinja_env, oids) for element in value]
  File "/Users/rubelagu/.pyenv/versions/3.10.7/envs/venv-airflow-250/lib/python3.10/site-packages/airflow/models/abstractoperator.py", line 657, in <listcomp>
    return [self.render_template(element, context, jinja_env, oids) for element in value]
  File "/Users/rubelagu/.pyenv/versions/3.10.7/envs/venv-airflow-250/lib/python3.10/site-packages/airflow/models/abstractoperator.py", line 664, in render_template
    self._render_nested_template_fields(value, context, jinja_env, oids)
  File "/Users/rubelagu/.pyenv/versions/3.10.7/envs/venv-airflow-250/lib/python3.10/site-packages/airflow/providers/cncf/kubernetes/operators/kubernetes_pod.py", line 321, in _render_nested_template_fields
    self._do_render_template_fields(content, ("value", "name"), context, jinja_env, seen_oids)
  ...
  ...
  File "/Users/rubelagu/.pyenv/versions/3.10.7/envs/venv-airflow-250/lib/python3.10/site-packages/airflow/models/variable.py", line 141, in get
    raise KeyError(f"Variable {key} does not exist")
KeyError: 'Variable nonexisting does not exist'
```

this happens when there is any error on the templates. For example
a `KeyError` raised when using `var.value.somemistypedvalue`:

```
        env_vars={
            "password": "{{ conn.test_connection.password }}",
            "VAR2": "{{ var.value.nonexisting}}",
        },
```

This PR uses the `airflow.utils.log.secrets_maker.redact` to remove any
field contained in `DEFAULT_SENSITIVE_FIELDS` or
`sensitive_var_conn_names`.

Co-authored-by: Andrey Anshin <Andrey.Anshin@taragol.is>