Move Renovate configuration to .github and configure automerge and codeowners

[ctreffs]

Context & Summary

What

• Relocated the Renovate configuration file from the repository root renovate.json to .github/renovate.json.
• Added "reviewersFromCodeOwners": false to the Renovate configuration.
• Configured "automerge": true and "automergeType": "pr" for non-major (minor, patch) GitHub Actions dependency updates.

Why

• Review Assignments & Email Notifications: Automatically requested reviews from /CODEOWNERS triggered unwanted email notifications on Renovate PRs. Adding "reviewersFromCodeOwners": false prevents Renovate from assigning reviewers based on /CODEOWNERS.
• Automerge: Automatically merges minor and patch GitHub Actions updates once CI checks pass, reducing manual overhead while complying with GitHub branch protection PR requirements.
• Repository Organization: Places the configuration file in the standard .github/ folder alongside GitHub Actions workflow definitions.

Where

• .github/renovate.json (moved from renovate.json)

---

Reviewer Guidance

How to Test / Verify

1. Run local validation:

   npx --yes --package renovate -- renovate-config-validator .github/renovate.json

2. Confirm the validator reports successful validation with zero warnings or errors.

Risk of Regression

• Low: Changes only affect Renovate execution options. Non-major GitHub Actions updates will automerge after CI passes; major version updates continue to require manual review.

Focus Areas

• .github/renovate.json: Confirm reviewersFromCodeOwners, automerge, and automergeType settings align with repository policies.