observation: disable SRC_TRACE_LOG by default
Created by: bobheadxi
See https://github.com/sourcegraph/sourcegraph/pull/34456#discussion_r894935250 . In hindsight this should be only-optin since we risk spamming log output.
PR to enable this explicitly in Cloud for Datadog: https://github.com/sourcegraph/deploy-sourcegraph-cloud/pull/16872
Test plan
n/a