[Bug]: Project Configuration not saving Production Branch

### Problem description

In the settings section if I change Production Branch then come back into the settings its reverted back to `main`. There is no way to save the selected branch

### Steps to reproduce

1. Login to Deno Deploy
2. Go to a project
3. Go to the settings tab
4. Change the production branch
5. Go to another tab/navigate away from the page
6. Return to the settings tab

### Expected behavior

Changing the production branch should either save automatically or offer a save button and then show the newly saved branch on returning to the settings area

### Environment

-OS [macOS 14.4.1 (23E224)
-Browser [Chrome Version 124.0.6367.91 (Official Build) (x86_64)]

### Possible solution

_No response_

### Additional context

If I tick `Use the legacy Git Integration UI` then the correctly selected branch does show