Cuts down the time to run integration tests in several ways:

- Build the Go binaries on the host system, allowing for reuse of cached artifacts (build, go mod, etc.)
- Use smaller Docker containers. We go from needing to pull golang and envoyproxy/envoy to pulling alpine and envoyproxy/envoy-alpine, which results in substantially shorter download times
- Set the grace period of the envoy container to 0, this issues a KILL immediately instead of waiting for up to 10s for envoy to handle a TERM