Fix incorrect commit status text on main project page
What does this MR do?
This MR fixes incorrect commit status text on main project page.
_last_commit partial was using incorrect helper. In this merge request we implemented a valid helper.
This is a quick fix before introducing detailed commit statuses, see #31239.
Does this MR meet the acceptance criteria?
- Changelog entry added
- Tests added for this bug
What are the relevant issue numbers?