dev/ci: do *not* run e2e sourcegraph/server tests with DEPLOY_TYPE=dev

Created by: slimsag

It appears that we introduced this in this PR and, although there is no description, the intent was to prevent this code from running.

However, it appears that code was never merged - at least blame says it has not existed since Sourcegraph became open source.

Also, the code is already protected by the user agent check - so I don't think we need this.

Most importantly: having DEPLOY_TYPE=dev is incredibly bad because it means we are not e2e testing the actual version of Sourcegraph we are releasing! conf.IsDeployTypeSingleDockerContainer() will return false when this is set, and various dev-only features will be turned on.

I only caught this because my PR to run some code in dev-only mode failed.

Helps #17218 (closed)

Signed-off-by: Stephen Gutekanst [email protected]