### 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)

)
        
        last_finish_time = freezed_base_time - timedelta(seconds=10)
        manager._file_stats = {
            "file_1.py": DagFileStat(1, 0, last_finish_time, timedelta(seconds=1.0), 1),
        }
        with freeze_time(freezed_base_time):
            manager.set_file_paths(dag_files)
            assert manager._file_path_queue == []
            
            manager.prepare_file_path_queue()
            assert manager._file_path_queue == []
        
        
        file_1_new_mtime = freezed_base_time - timedelta(seconds=5)
        file_1_new_mtime_ts = file_1_new_mtime.timestamp()
        with freeze_time(freezed_base_time):
            manager.set_file_paths(dag_files)
            assert manager._file_path_queue == []
            
            mock_getmtime.side_effect = [file_1_new_mtime_ts]
            manager.prepare_file_path_queue()
            
            assert manager._file_path_queue == ["file_1.py"]
            assert last_finish_time < file_1_new_mtime
            assert (
                manager._file_process_interval
                > (freezed_base_time - manager.get_last_finish_time("file_1.py")).total_seconds()
            )
    def test_deactivate_stale_dags(self):