test(agent-core): remove stale windows kill todo

[xianjianlf2]

Related Issue

No linked issue.

Problem

A Windows-only it.todo for process-tree termination lived in agent-core even though the behavior is already covered by kaos process tests.

What changed

Remove the stale todo-only test file so the test tree reflects the current coverage surface.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

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Latest commit: fe07eca

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