codeintel: Add a (temporary) lock around ignite run
Created by: efritz
We've recently seen some issues with concurrent VM creation in Cloud. I'm adding a lock around ignite run which starts a VM and waits for it to boot. This can later be replaced with something that pulls all the deps once (on demand or before the worker starts dequeueing work).
Following up in https://github.com/sourcegraph/sourcegraph/issues/21377