Follow up: breaking changes in the Profiling protocol

With https://github.com/open-telemetry/opentelemetry-proto/pull/576 it is proposed to exclude the Profiling protocol from the breaking-changes test.

Currently the Profiling protocol is marked as experimental and breaking changes are accepted. But once, the Profiling protocol is declared stable, https://github.com/open-telemetry/opentelemetry-proto/pull/576 needs to be reverted.

spec:profiles