Require attributes and event fields to have stability

[lmolkova]

See open-telemetry/semantic-conventions#1777 - we don't validate that stability is present on attributes or event fields

[jerbly]

@lmolkova looks like we're also not enforcing stability on enum members of event fields: https://github.com/open-telemetry/semantic-conventions/blob/main/model/device/events.yaml#L36

I assume we want this fixed too?

[lmolkova]

@jerbly great catch! yes, explicit stability everywhere it matters is the goal :)

[jerbly]

At the moment the Weaver code, EBNF and semconv.schema.json all define the body of the event as an any_value. Some any_values can contain any_values. Therefore the body itself is required to have stability defined. This is missing in every use of body in the current semconvs.

    body:
      id: device_lifecycle_state
      type: map
      requirement_level: required
      stability: experimental # <-------------- This is also required
      fields:
        - id: ios.state
          stability: experimental
          type: enum
          ...