[BUG] Pushing an new branch with no new commits to GitHub does not update the list of branches in Pipedream's UI

**Describe the bug**
I have a Pipedream Project using GitHub Sync, and the webhook is working. I have a feature branch with work on it that is waiting for PR review, so I created a new branch off of it that I want to edit in Pipedream (to add another step to an existing workflow, for a future PR). The GitHub webhook did fire (telling Pipedream about the new branch) and received a 200 response from Pipedream. However, the new branch is not showing up in Pipedream's UI (in the dropdown by Edit or in the View All Branches dialog) and that GitHub event is not showing in the Changelog in Pipedream's UI. When I added another commit to that branch and pushed that to GitHub, then the new branch showed up in Pipedream.

**To Reproduce**
Steps to reproduce the behavior:

1. Create a non-production branch on a GitHub-Synced Pipedream project.
2. Add commits to that branch, push the branch to GitHub.
3. Make a new branch off of that one, and push that new branch without adding any new commits to it.
4. See in the GitHub repo's Settings that the webhook fired.
5. See that the new branch is not in the list of branches on Pipedream, and that the Pipedream project's Changelog records no event for that webhook call.

**Expected behavior**
I expected the new branch to show up in Pipedream's UI so I could start adding commits to it there.

**Screenshots**
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**Additional context**
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Thanks.

Start by tracing the GitHub webhook handling for branch creation and the code that populates the branch dropdown, View All Branches dialog, and Changelog. Reproduce the described push of a branch with no new commits, then compare it with a push containing a commit. Done means the webhook is recorded and the new branch appears in the UI.

Written by the indexing model from the issue text.