engineering: Welcome to the Cloud team, @asdine!

Created by: tsenart

This PR updates the team memberships of the search and cloud teams to have @asdine join our efforts on RFC 151 roadmap.

Asdine will wrap up his search team work this week on More efficient and-operator evaluation and then begin on a key effort in our Sourcegraph Cloud roadmap: Store Git commits in Postgres #11169

For more details, please check our 3.18 tracking issue.

I'm excited to welcome Asdine on the Cloud team :)