docs: keep ADR 0003 out of action release sync

[hesreallyhim]

Summary

• remove ADR 0003 from action-release managed text rewrites
• replace the concrete current action ref in ADR 0003 with a pointer to template-action-release.yml
• add a regression test that decision records stay out of release sync and avoid concrete action refs

Verification

• git diff --check
• venv/bin/python -m ruff check scripts/sync_action_release.py tests/test_generated_repos.py
• make verify-action-release
• venv/bin/python -m pytest tests/test_generated_repos.py
• venv/bin/python -m mypy --python-version 3.11 scripts/sync_action_release.py tests/test_generated_repos.py

[hesreallyhim]

lgtm