dev/ci: clean up deployment logic to dogfood/prod
Created by: ggilmore
This PR does not need to update the CHANGELOG because this PR has no user-facing changes
Previously, this line: https://github.com/sourcegraph/sourcegraph/blob/34bbc85e55581afcc0354fe374e4739ef07323d0/dev/ci/gen-pipeline.go#L245-L246 was a no-op since https://github.com/sourcegraph/sourcegraph/blob/34bbc85e55581afcc0354fe374e4739ef07323d0/dev/ci/gen-pipeline.go#L199-L203
is the inverse of that conditional.
Also, the deploy
variable + associated logic in addDeploySteps
could be simplified by just using an early return
statement.
This PR address both of these issues.