[k8s] Promote a selection of k8s/container attributes to stable

[ChrsMark]

Changes

⚠️ The graduation of these attributes is needed for Promote k8sattributes Processor to Stable #44483.

This PR promotes a selection of K8s and Container attributes to stable.

Similar to #3491.

I suggest we consider the graduation of these attributes to stable taking into account the following:

• RC promotion d826cc9 was landed on March 9th
• RC promotion was advertised to the community with https://opentelemetry.io/blog/2026/k8s-semconv-rc/ (March 16th)
• RC promotion was highlighted during KubeCon's project updates
• The graduation process for these attributes started with Promote a selection of k8s and container attributes to alpha #3215 (Dec 15, 2025)

Based on the above, the intention has been quite clear already and enough period for feedback has been provided.

open-telemetry/opentelemetry-collector-contrib#48413 has already adopted the release_candidate Semantic Conventions in the k8s_attributes processor of the Collector.

This is part of #3120.
Fixes #3382.

All suggested attributes are already in use from several Collector components as described at #3120 (comment):

• k8sattributes processor (from metadata.yaml and extract::metadata)
• resourcedetection processor
• filelog receiver

Important

Pull requests acceptance are subject to the triage process as described in Issue and PR Triage Management.
PRs that do not follow the guidance above, may be automatically rejected and closed.

Merge requirement checklist

• CONTRIBUTING.md guidelines followed.
• Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• Links to the prototypes or existing instrumentations (when adding or changing conventions)

/cc @open-telemetry/semconv-k8s-approvers @jmmcorreia @skl

[ChrsMark]

@dmitryax @jinja2 I'm adding you explicitly as reviewers. Since this is a PR moving attributes to stable your approvals would be needed so as to ensure it's approved by the majority of the @open-telemetry/semconv-k8s-approvers.

[mx-psi]

I have not been participating in the SIG so my approval should not count much but to the extent that I still have the approver title officially I will approve this :)