[Bug]: /api/project/<project>/runs/stop ignores nonexistent runs_names

[jvstme]

Steps to reproduce

> curl -v http://localhost:3000/api/project/main/runs/stop \
                       -H "Content-Type: application/json" \
                       -H "Authorization: Bearer *****" \
                       -d '{"runs_names": ["aoaoooaoa"], "abort": false}'

Actual behaviour

< HTTP/1.1 200 OK
< date: Tue, 18 Feb 2025 13:54:28 GMT
< server: uvicorn
< content-length: 4
< content-type: application/json
< 
* Connection #0 to host localhost left intact
null

Expected behaviour

Error, run aoaoooaoa not found.

dstack version

0.18.42

Server logs

DEBUG    dstack._internal.server.app:220 Processed request POST http://localhost:3000/api/project/main/runs/stop in 0.130156s. Status: 200

Additional information

Correct error reporting will help find and debug issues like #2315 more easily.