server:latest -> server:CURRENT_VERSION everywhere

Created by: dadlerj

Is there a reason why we use :latest in all of the cloud host deployment docs? I think it's a bit irresponsible to recommend using our insiders/RC for "production" deployments (i.e., when users deploy to cloud hosts).

Also, it's just generally inconsistent with other parts of the docs.

cc @KattMingMing

Created by: dadlerj

Also, non-official releases break update checks (so, if I'm not mistaken, they'll never get a notification to upgrade):

Created by: dadlerj

Hah — looks like this issue has already been solved! https://github.com/sourcegraph/website/blob/master/src/components/ServerVersionNumber.tsx

I'll update this PR

I found this component, by the way, from the server release process doc @slimsag

Created by: dadlerj

No idea why CI is failing across the board. Seems unrelated to this PR.

This removes all hardcoded sourcegraph/server:latest instances and replaces them with sourcegraph/server:<server-version-number />, updating which is part of our existing release process @slimsag

I also removed sourcegraph.yaml, a file that doesn't seem to have been used since the day it was added in a PR ~9 months ago (which I only discovered because it referenced sourcegraph/server:latest).

Created by: dadlerj

Thanks!

Created by: attfarhan

@nicksnyder you can go to Netlify to see the build log. The logs aren’t public yet. You will need to merge or rebase off of master to get this to pass, as I added to build script after this PR was opened.