Context

while I was searching for all the ways a candidate can get to the withdraw process, I came across this route which always redirects to either carry_over, or the application_choices path... But the application choices path redirects to carry_over if appropriate, so it wasn't necessary to keep this path alive. The complete.html.erb hasn't been used since continuous applications.

Changes proposed in this pull request

No UI changes. Everything is exactly the same.
This just removes a route.

Guidance to review

Click around and see if anything is broken.

Things to check

• If the code removes any existing feature flags, a data migration has also been added to delete the entry from the database
• This code does not rely on migrations in the same Pull Request
• If this code includes a migration adding or changing columns, it also backfills existing records for consistency
• If this code adds a column to the DB, decide whether it needs to be in analytics yml file or analytics blocklist, if included inform data insights team of the changes
• If this code adds a column that may include PII, the sanitise.sql script and 0025-protecting-personal-data-in-production-dump.md ADR have been updated.
• API release notes have been updated if necessary
• [] If it adds a significant user-facing change, is it documented in the CHANGELOG?
• Attach the PR to the Trello card