fix: renovate not updating node instrumentation Dockerfile

[Copilot]

Renovate's built-in workarounds preset (part of config:recommended) applies node versioning to the official node Docker image. With the default ignoreUnstable: true, odd-numbered Node.js majors (Current releases like 25) are treated as unstable and skipped. Since Node 26 doesn't exist yet, FROM node:24 sees no viable update → no PR, no log output.

This matters because build.yml reads the Dockerfile version as the upper bound for which Node.js versions to build modules for:

seq "$(min_version_from_packages)" \
    "$(grep '^FROM ' Dockerfile | cut -d: -f2)"

Changes

• .github/renovate.json: Add packageRule scoped to the dockerfile manager for the node image with ignoreUnstable: false, consistent with the existing equivalent rule for Python OpenTelemetry packages

Original prompt

the dockerfile in the node instrumentation is not updated by renovate. the dockerfile is only used for that purpose. we never build an image from it, but we use it to have renovate update the version so we know what's the latest node version is. however renovate doesn't update it. the logs say nothing. tell me why and fix it

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[plengauer]

Hello, thanks for contributing for the first time!

[Copilot]

Pull request overview

Adjusts Renovate configuration so it continues to update the dummy Node instrumentation Dockerfile tag even when the latest Node major is an odd-numbered “Current” release (treated as unstable by default), ensuring CI can derive the correct upper bound Node version for building Node modules.

Changes:

• Add a Renovate packageRule for the dockerfile manager targeting the node image with ignoreUnstable: false.