ci: Set COMMIT_SHA/DATE env vars when building server image
Created by: mrnugget
I noticed that when we build a server image in the e2e step we don't have access to the environment variables of the "main" build that triggered it.
See "Environment" tab here for example: https://buildkite.com/sourcegraph/e2e/builds/4746#d0b5e174-0c63-4f0c-a0ef-59fa27697a8c
The result was that COMMIT_SHA
and DATE
labels weren't set in the server images we built the .
This change here should fix that by only copying from the environment what's already set at runtime and copying from the build config what's set in the "main" build environment.