[prometheus] Stabilize Prometheus -> OTLP: Unknown

[dashpole]

Part of #4742

Changes

Stabilize the conversion of Prometheus Unknown metrics to OTLP

• Related issues [prometheus] Stabilize Prometheus -> OTLP specification #4742
• Related OTEP(s) #
• Links to the prototypes (when adding or changing features)
  • prometheus receiver implementation: https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/47b5da2e5c81f8da0eb470a8ce94961425fa0208/receiver/prometheusreceiver/internal/util.go#L133-L134
• CHANGELOG.md file updated for non-trivial changes
  • For trivial changes, include [chore] in the PR title to skip the changelog check
• Spec compliance matrix updated if necessary
• Declarative config data model is updated if SDK config surface is changed

[dashpole]

@open-telemetry/prometheus-interoperability

[ArthurSens]

LGTM! Any special reason for this to be still draft?

[opentelemetry-pr-dashboard]

Pull request dashboard status

Waiting on reviewers · refreshed 2026-09-01 16:35 UTC

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[dashpole]

LGTM! Any special reason for this to be still draft?

Marked it ready for review!