Automate PR compliance checks and duplicate/related PR detection

[pomfrida]

Background

Other repos use GitHub Actions bots to automate PR and issue triage. We could benefit from similar automation in EDS.

Proposed automations

1. PR compliance check

A bot that automatically checks new PRs against our contributing guidelines and PR template:

• Verifies that the PR description includes required template sections
• Adds a needs:compliance label if requirements are not met
• Posts a comment explaining what needs to be fixed
• Optionally auto-closes after a grace period if not addressed

This would help maintain PR quality and reduce manual review burden for maintainers.

2. Duplicate/related PR/issue detection (LLM-powered)

A bot that searches for potentially duplicate or related PRs/issues when a new PR or issue is opened:

• Uses an LLM to analyze the PR title, description, and changed files
• Searches existing PRs and issues for related work
• Posts a comment summarizing related PRs with links and relevance explanations
• Includes a disclaimer that the comment was generated by an LLM and may be inaccurate

This would help contributors and reviewers stay aware of overlapping work and avoid duplicated effort.

References

Inspiration from similar automation seen in other open-source repos using github-actions bots.