### 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)

"""Kill any file processors that timeout to defend against process hangs."""
        now = timezone.utcnow()
        processors_to_remove = []
        for file_path, processor in self._processors.items():
            duration = now - processor.start_time
            if duration > self._processor_timeout:
                self.log.error(
                    "Processor for %s with PID %s started at %s has timed out, killing it.",
                    file_path,
                    processor.pid,
                    processor.start_time.isoformat(),
                )
                Stats.decr("dag_processing.processes")
                Stats.incr("dag_processing.processor_timeouts")
                
                Stats.incr("dag_file_processor_timeouts")
                processor.kill()
                
                self.waitables.pop(processor.waitable_handle)
                processors_to_remove.append(file_path)
        
        for proc in processors_to_remove:
            self._processors.pop(proc)
    def max_runs_reached(self):