constraints allows to formalize that at least one of attributes should be present.

We're getting away from this approach in semconv and usually define an attribute that's always available. Otherwise we use requirement level and notes mechanism to clarify when/how attributes should be populated.

As a result, we use constraints in a very few places in the semconv and it would be great to

• check if we need them there. If we do, we should consider improving markdown rendering (now they appear as See below in the Requirement Level and conflict with ReqLevel on the attribute.
• or remove them from the yaml schema and tooling.