### Apache Airflow version

2.4.1

### What happened

When there are large number of dag files, lets say 10K and each takes sometime to parse,  dag_parser doesnt pick any newly created files till all 10k files are finished parsing

`if not self._file_path_queue:
                self.emit_metrics()
                self.prepare_file_path_queue()`

Above logic only adds new files to queue when queue is empty

### What you think should happen instead

Every loop of dag processor should pick new files and add into file for parsing queue

### How to reproduce

_No response_

### Operating System

All

### Versions of Apache Airflow Providers

_No response_

### Deployment

Docker-Compose

### Deployment details

_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)

"""Occasionally print out stats about how fast the files are getting processed"""
        if 0 < self.print_stats_interval < time.monotonic() - self.last_stat_print_time:
            if self._file_paths:
                self._log_file_processing_stats(self._file_paths)
            self.last_stat_print_time = time.monotonic()
    @provide_session
    def clear_nonexistent_import_errors(self, session):
        """
        Clears import errors for files that no longer exist.
        :param session: session for ORM operations
        """
        query = session.query(errors.ImportError)
        if self._file_paths:
            query = query.filter(~errors.ImportError.filename.in_(self._file_paths))
        query.delete(synchronize_session="fetch")
        session.commit()
    def _log_file_processing_stats(self, known_file_paths):
        """
        Print out stats about how files are getting processed.
        :param known_file_paths: a list of file paths that may contain Airflow
            DAG definitions
        :return: None
        """