Can't select the desired dag version for a backfill dag run

### Apache Airflow version

3.0.0

### If "Other Airflow 2 version" selected, which one?

_No response_

### What happened?

I am making a bunch of edits to a dag, and I want to re-run a backfill for a specified date range. When I do, Airflow performs the backfill with the version of the dag that originally ran, and there's seemingly no way in the UI to specify that I want to re-run using the latest dag version.

### What you think should happen instead?

The latest version should maybe be the default version for backfills, and users should be able to select the version that runs.

### How to reproduce

1. Run a backfill over a certain date.
2. Update the dag code
3. Run a backfill over the same date from (1)

### Operating System

n/a

### Versions of Apache Airflow Providers

n/a

### Deployment

Astronomer

### Deployment details

_No response_

### Anything else?

_No response_

### 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)

No files, tests, or entry points are named in the report. Start by tracing the UI backfill flow and how DAG versions are selected, then define and test the expected behavior for choosing the latest or another specified version.

Written by the indexing model from the issue text.