### Apache Airflow version

main (development)

### Operating System

macOS 11.5.2

### Versions of Apache Airflow Providers

_No response_

### Deployment

Virtualenv installation

### Deployment details

_No response_

### What happened

If your first try fails and you have retries enabled, the subsequent tries skip right to the final `next_method(**next_kwargs)` instead of starting with `execute` again.

### What you expected to happen

Like we reset things like start date, we should wipe `next_method` and `next_kwargs` so we can retry the task from the beginning.

### How to reproduce

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

tests/models/test_taskinstance.py
"""
        Test the availability of variables in templates
        """
        Variable.set('a_variable', 'a test value')
        ti = create_task_instance()
        context = ti.get_template_context()
        result = ti.task.render_template(content, context)
        assert result == expected_output
    def test_template_with_variable_missing(self, create_task_instance):
        """
        Test the availability of variables in templates
        """
        ti = create_task_instance()
        context = ti.get_template_context()
        with pytest.raises(KeyError):
            ti.task.render_template('{{ var.value.get("missing_variable") }}', context)
    @pytest.mark.parametrize(
        "content, expected_output",
        [
            ('{{ var.value.a_variable }}', '{\n  "a": {\n    "test": "value"\n  }\n}'),
            ('{{ var.json.a_variable["a"]["test"] }}', 'value'),
            ('{{ var.json.get("a_variable")["a"]["test"] }}', 'value'),
            ('{{ var.json.get("a_variable", {"a": {"test": "unused_fallback"}})["a"]["test"] }}', 'value'),
            ('{{ var.json.get("missing_variable", {"a": {"test": "fallback"}})["a"]["test"] }}', 'fallback'),
        ],
    )
    def test_template_with_json_variable(self, content, expected_output, create_task_instance):