"Branch or commit" dropdown is empty and does not show options when switching to a Repository that does not contain the previously selected branch name

Steps to reproduce:

1. Open Unity Hub
2. In the Projects tab, click Add > Add from repository
3. Select Gitub or GitLab as Source control provider and Authorize token (if not previously authorized)
4. Select a Repository that contains a unique branch name (e.g. test)
5. Select that branch in the "Branch or commit" field
6. Select another Repository that does not contain the previously selected branch name
7. Click on and observe the Branch field

Actual results: The Branch field appears empty, clicking it does not show any branch options in the dropdown

Expected results:  "Branch or commit" field should reset or clear when another Repository is selected

Reproducible with versions: 3.17.2

Tested on (OS): Ubuntu 24.04, macOS 26.4

Notes:

• The field refreshes once text is entered into the field or the X button is pressed to clear it. This suggests stale state is kept after switching repositories