### What do you see as an issue?

The documentation for zombie tasks https://airflow.apache.org/docs/apache-airflow/stable/core-concepts/tasks.html#zombie-undead-tasks is a bit abstract at the moment. There is a scope for enhancing the document by explaining how Airflow detects tasks as zombies

### Solving the problem

We can enhance the documentation by translating this query https://github.com/astronomer/airflow/blob/main/airflow/jobs/scheduler_job_runner.py#L1721 to a layman readable text in our documentation.

### Anything else

It might also help to add developer contribution steps to reproduce zombies locally.

### Are you willing to submit PR?

- [ ] 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)

"""
        Enqueue task_instances which should have been set to queued with the executor.
        :param task_instances: TaskInstances to enqueue
        :param session: The session object
        """
        
        for ti in task_instances:
            if ti.dag_run.state in State.finished_dr_states:
                ti.set_state(None, session=session)
                continue
            command = ti.command_as_list(
                local=True,
                pickle_id=ti.dag_model.pickle_id,
            )
            priority = ti.priority_weight
            queue = ti.queue
            self.log.info("Sending %s to executor with priority %s and queue %s", ti.key, priority, queue)
            self.job.executor.queue_command(
                ti,
                command,
                priority=priority,
                queue=queue,
            )
    def _critical_section_enqueue_task_instances(self, session: Session) -> int: