insights: turn on for Sourcegraph.com
Created by: slimsag
This PR turns on insights code Sourcegraph.com only (not customer deployments, not our dogfood deployment, etc.)
Rollout should go smoothly, but in case it doesn't there is an escape hatch
DISABLE_CODE_INSIGHTS=true
we can set to disable it. Only reason not to turn
on for all customers currently is because the PR for TimescaleDB in Docker Compose
hasn't yet been sent - that will come in the next day or so.