Resolve "Breadcrumb links to 404 page"

What does this MR do?

• Fix incorrect breadcrumbs path for group import status page (see #300367 (closed))

Testing guidelines

• Enable feature bulk_imports via Feature.enable(:bulk_imports)
• Open "New group" (/groups/new)
• Use https://gitlab.com as source instance and GeK1Nis4j-SY1X4sqE5c as personal access token (this token is from separate user on GitLab instance with 0 real data available, so we do not expose any security risks here)
• Click "New Group" breadcrumb

You should be taken to /groups/new page

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