opt-in for js and .io for PR dashboard

[maryliag]

Add opentelemetry-js, opentelemetry-js-contrib and opentelemetry.io to the list of repos for the PR Dashboard.
Keep the names in alphabetical order.

The added repos are on the list of "repository access" under settings for the app

[Copilot]

Pull request overview

This PR opts three additional open-telemetry repositories into the PR Dashboard by adding them to repositories.json. The dashboard workflow builds its job matrix from this file (.github/workflows/pull-request-dashboard.yml), so each new entry causes the dashboard to track and route PRs for that repository. The entries also reorder the list so that opentelemetry-java-instrumentation (previously last) is grouped with the other opentelemetry-* repos, keeping the list alphabetized.

Changes:

• Adds opentelemetry-js and opentelemetry-js-contrib (mapped to javascript-approvers) and opentelemetry.io (mapped to docs-approvers).
• Moves opentelemetry-java-instrumentation to the top to preserve alphabetical ordering of repository names.

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[trask]

Also need to add these repos here: https://github.com/organizations/open-telemetry/settings/installations/133550497

[maryliag]

I added but didn't click on save 🤦
done now