Fix flaky windows test

[dedrisian-oai]

There are exactly 4 types of flaky tests in Windows x86 right now:

1. review_input_isolated_from_parent_history => Times out waiting for closing events
2. review_does_not_emit_agent_message_on_structured_output => Times out waiting for closing events
3. auto_compact_runs_after_token_limit_hit => Times out waiting for closing events
4. auto_compact_runs_after_token_limit_hit => Also has a problem where auto compact should add a third request, but receives 4 requests.

1, 2, and 3 seem to be solved with increasing threads on windows runner from 2 -> 4.

Don't know yet why # 4 is happening, but probably also because of WireMock issues on windows causing races.

[dedrisian-oai]

@bolinfest Lmk if it looks good, I'll revert the CI script changes before merging.