Remove obsolete upload_diff_form from review request context.
Review Request #13692 — Created April 2, 2024 and submitted — Latest diff uploaded
The review request template context was still including the old
upload_diff_form, which has long been supplanted by a pure-JS
implementation. This change removes it.
- Ran unit tests.
- Grepped to make sure that there were no uses of
upload_diff_form.