assistant: Strip out general website chrome in `/fetch` command (#13264)

This PR updates the `/fetch` command to strip out general website chrome
that likely won't contain content on any websites.

Release Notes:

- N/A
ddf07253c4Marshall Bowers committed on 6/19/2024, 1:50:02 PM· committed by GitHubparentaff7a83
2 files changedLine totals unavailable