Auto find spector PR and auto trigger AI agent to add test case

[msyyc]

Current flow:
https://github.com/msyyc/typespec/actions/workflows/python-check-spec-tests.yml find merged spector PR then create an github issue and assign to Copilot, finally there will be a PR for language owner to review

Effect

https://github.com/msyyc/typespec/actions/runs/22754465508 find merged spector PR then created issue #9948 and assign to Copilot, finally language owner got an PR #9949 to review.