### Description


We need to access the time at which a given DAG was parsed last.

Airflow Version : 2.2.2 and above.

### Use case/motivation

End users want to run a given DAG post applying the changes they have done on them. This would mean that the DAG should be parsed post the edits done to it. Right now the last parsed time is available by accessing the airflow database only. Querying the database directly is not the best solution to the problem. Ideally airflow should be exposing APIs that end users can consume that can help provide the last parsed time for a given DAG.

### Related issues

Not Aware.

### Are you willing to submit a 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)

classes += (CeleryKubernetesExecutor,)
                except ImportError:
                    pass
                if not issubclass(executor_cls, classes):
                    message = (
                        f"celery subcommand works only with CeleryExecutor, CeleryKubernetesExecutor and "
                        f"executors derived from them, your current executor: {executor}, subclassed from: "
                        f'{", ".join([base_cls.__qualname__ for base_cls in executor_cls.__bases__])}'
                    )
                    raise ArgumentError(action, message)
        if action.dest == "subcommand" and value == "kubernetes":
            try:
                import kubernetes.client  
            except ImportError:
                message = (
                    "The kubernetes subcommand requires that you pip install the kubernetes python client. "
                    "To do it, run: pip install 'apache-airflow[cncf.kubernetes]'"
                )
                raise ArgumentError(action, message)
        if action.choices is not None and value not in action.choices:
            check_legacy_command(action, value)
        super()._check_value(action, value)
    def error(self, message):
        """Override error and use print_instead of print_usage."""
        self.print_help()
        self.exit(2, f"\n{self.prog} command error: {message}, see help above.\n")
_UNSET = object()
class Arg:
    """Class to keep information about command line argument."""
    def __init__(