We need to monitor upstream tests (from envoy and envoy-wasm) for any problems in our build. This is possible since we may change the base workspace and dependencies do not match. Envoy is fairly sensitive to particular versions of its libraries (e.g. absl).

I think we should add a post-submit here and the testgrid for this purpose, since there is no need to run this on every pre-submit (upstream dependency SHA does not change that often).