Versioned metrics: Shipping the first Release Candidate metrics in hostmetrics

OpenTelemetry Collector Contrib v0.160.0 introduces versioned metrics to the hostmetrics receiver, enabling a seamless transition to new semantic conventions without breaking existing user configurations. By utilizing versioned suffixes and feature gates within a single configuration schema, the collector can simultaneously emit both legacy and release candidate metrics. This approach provides a controlled, opt-in migration path for updates to metric names, types, and attributes.