assistant: Clean up completion building in `/docs` command (#13877)

This PR cleans up the building of completions in the `/docs` command a
bit after #13876.

Release Notes:

- N/A
950e7e5414Marshall Bowers committed on 7/5/2024, 5:42:27 PM· committed by GitHubparent68accae
1 file changedLine totals unavailable