Fix `contributors.yml` Workflow

## MENTOR
- @IsaacMilarky
- USDC DSACMS SWE
- Slack or email

## BRIEF DESCRIPTION
Currently, the `contributors.yml` workflow doesn't work and triggers itself forever.

What happens is that it is triggered on push to main, but then it pushes changes to the main branch which triggers itself again forever. https://github.com/DSACMS/metrics/actions/workflows/contributors.yml

This also creates a PR every time the workflow runs.

## SCOPING
- days

## SKILLS NEEDED
GitHub Actions and scripting.

## REQUIRED DELIVERABLES

1. Stop the workflow from triggering itself
2. Set up a workflow to automatically update main as it is a protected branch
3. Verify that the contributor information is automatically updated on each legitimate push to main or otherwise

## DESIRED DELIVERY WINDOW
- Any

# ACKNOWLEDGEMENTS
- [X] - Yes, I agree to spend file a project proposal ticket
- [X] - Yes, I agree this project falls within a 2 week or less (ideally less) scope of time
- [X] - Yes, I agree to spend an hour per week of office hours and 1x1 mentoring
- [ ] - Yes, I agree to spend an hour at the end of the sprint for filling out a Retro Template