### 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)

"""
    Dataclass to represent concurrency maps.
    It contains a map from (dag_id, task_id) to # of task instances, a map from (dag_id, task_id)
    to # of task instances in the given state list and a map from (dag_id, run_id, task_id)
    to # of task instances in the given state list in each DAG run.
    """
    dag_active_tasks_map: dict[str, int]
    task_concurrency_map: dict[tuple[str, str], int]
    task_dagrun_concurrency_map: dict[tuple[str, str, str], int]
    @classmethod
    def from_concurrency_map(cls, mapping: dict[tuple[str, str, str], int]) -> ConcurrencyMap:
        instance = cls(Counter(), Counter(), Counter(mapping))
        for (d, r, t), c in mapping.items():
            instance.dag_active_tasks_map[d] += c
            instance.task_concurrency_map[(d, t)] += c
        return instance
def _is_parent_process() -> bool:
    """
    Whether this is a parent process.
    Return True if the current process is the parent process.
    False if the current process is a child process started by multiprocessing.
    """
    return multiprocessing.current_process().name == "MainProcess"
class SchedulerJobRunner(BaseJobRunner, LoggingMixin):