ci: give codeinsights-db a very generous DB_STARTUP_TIMEOUT
Created by: bobheadxi
Test sometimes fail with being unable to connect to this DB, this is a crude stopgap that bumps the timeout to give it more time to start up. https://sourcegraph.slack.com/archives/C01N83PS4TU/p1639411400449400
That said, this doesn't actually seem to fail all that often (just a few affected builds over the past week) so I think this is fine for now