chore(caretaker): remove obsolete .github/workflows/maintainer.yml

[ianlintner]

The runner-side maintainer.yml workflow is now obsolete:

• The caretaker GitHub App delivers webhooks to the backend in real time.
• The backend has its own reconciliation scheduler (30-min cadence) — replaces the sparse cron in this workflow.
• All execution happens backend-side; this file does no actual work.

Repo-side artifacts that stay (consumed by the backend / Copilot hand-offs):

• .github/maintainer/config.yml — repo configuration
• .github/maintainer/.version — version pin
• .github/agents/*.md — agent personas
• .github/copilot-instructions.md

Upstream change: ianlintner/caretaker#638 (template + bootstrap agent updated to stop scaffolding this file going forward).

🤖 Generated with Claude Code

[care-taker-bot]

⚠️ Caretaker Escalation

This PR requires human attention.

Reason: Open >24h with no human approval — needs review

The automated system has exhausted its ability to resolve this. Please review and take appropriate action.

Escalation debug dump

Generated at: 2026-04-29T19:00:56.587043+00:00

{
  "debug": {
    "copilot_attempts": 0,
    "fix_cycles": 0,
    "pr_age_hours": 27.703271808055554,
    "recommended_action": "escalate",
    "stuck_age_hours": 24,
    "stuck_confidence": 0.5,
    "stuck_reason": "abandoned"
  },
  "owner": "ianlintner",
  "pull_request": {
    "base_ref": "main",
    "draft": false,
    "head_ref": "fix/caretaker-github-pypi-name",
    "html_url": "https://github.com/ianlintner/python_dsa/pull/67",
    "is_copilot_pr": false,
    "is_maintainer_pr": false,
    "mergeable": null,
    "number": 67,
    "state": "open",
    "title": "chore(caretaker): remove obsolete .github/workflows/maintainer.yml"
  },
  "reason": "Open >24h with no human approval \u2014 needs review",
  "repo": "python_dsa",
  "type": "pr_escalation"
}

[care-taker-bot]

⚠️ Caretaker Escalation

This PR requires human attention.

Reason: Open >24h with no human approval — needs review

The automated system has exhausted its ability to resolve this. Please review and take appropriate action.

Escalation debug dump

Generated at: 2026-05-05T19:00:13.457165+00:00

{
  "debug": {
    "copilot_attempts": 0,
    "fix_cycles": 0,
    "pr_age_hours": 171.69136044777778,
    "recommended_action": "escalate",
    "stuck_age_hours": 24,
    "stuck_confidence": 0.5,
    "stuck_reason": "abandoned"
  },
  "owner": "ianlintner",
  "pull_request": {
    "base_ref": "main",
    "draft": false,
    "head_ref": "fix/caretaker-github-pypi-name",
    "html_url": "https://github.com/ianlintner/python_dsa/pull/67",
    "is_copilot_pr": false,
    "is_maintainer_pr": true,
    "mergeable": null,
    "number": 67,
    "state": "open",
    "title": "chore(caretaker): remove obsolete .github/workflows/maintainer.yml"
  },
  "reason": "Open >24h with no human approval \u2014 needs review",
  "repo": "python_dsa",
  "type": "pr_escalation"
}