[Bug]: Deno Deploy fails with "An internal server error occurred." while git integration

### Problem description

Unable to integrate Git with Deno after creating a new project. Additionally, I am unable to change the Git branch integrated with Deno in another project.


### Steps to reproduce

In the project settings, integrate Git to link this project to a GitHub repository, enabling automatic deployment on push

### Expected behavior

I expect the Git integration to proceed without any errors.

### Environment

_No response_

### Possible solution

_No response_

### Additional context

_No response_

Start by reproducing the failure from project settings while linking a project to a GitHub repository, and separately test changing the integrated branch in another project. Compare both flows and the resulting internal server error; done means Git integration completes and branch changes work without errors.

Written by the indexing model from the issue text.