Bulk add previews that completely fail to fetch any videos can get their response cached

[dyc3]

Current Behavior

It's possible for a bulk add preview, one with multiple links separated by newlines, to fail to get all of the videos requested. In this case, the add preview will still succeed, and the result will get cached. This will cause the user to be unable to get a fresh add preview

Expected Behavior

If grabbing all the videos fails, the add preview should fail with a non-200 status code, and exclude any caching headers.

Steps To Reproduce

Recommended: use miniserve to serve files over http

1. In the add preview box, paste 2 links to non existent videos
2. Wait for add preview to complete
3. Bring up a webserver to serve videos to make the links in the add preview valid
4. Refresh the add preview
5. See the previous result remain

Environment

• This happens on the official site, opentogethertube.com
• This happens using a self-hosted version.
• I'm using the docker image.

Anything else?

No response