Clarify on if schemaUrl is part of InstrumentationLibrary

[legendecas]

What are you trying to achieve?

Ref: open-telemetry/opentelemetry-js#2625 (comment)

In the spec, there are no clear statements about what an instrumentation library info consists of. Likely the InstrumentationLibrary should contain name and version, but the schemaUrl is not clearly stated if it is part of them.

I do find statements like the following that treat those three elements as one pack.

Implementations MUST NOT require users to repeatedly obtain a Meter again with the same name+version+schema_url to pick up configuration changes
https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/api.md#get-a-meter

Additional context.

Links:

• https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/overview.md#instrumentation-libraries
• https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/glossary.md#instrumentation-library