Use weaver live-check in CI to ensure internal instrumentation follows OTel conventions

[cijothomas]

#1605 (review)

Let's follow what we advise everyone to follow!
For internal Events, there aren't any conventions defined yet. But for internal metrics, there are some defined for OTel SDKs, which could be followed? (https://github.com/open-telemetry/semantic-conventions/blob/main/docs/otel/sdk-metrics.md)