Fix failure in squash_merge_request_spec by reloading page if commit does not appear

What does this MR do?

In the failed test the events API reported that the push succeeded, so we reload the UI because it initially wasn't shown.

Closes #37924 (closed)

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers