On Windows, the panic hook generated a minidump by calling
`simulate_exception`, but that function only invokes the crash callback
and then returns. Rust could therefore unwind a panicking background
thread while leaving the rest of the application running.

Abort unconditionally after minidump generation, matching the existing
Linux and macOS behavior. The Windows-specific simulation still runs
first so the crash sidecar can persist the exception context and panic
metadata before the process terminates.

Testing:

- `cargo fmt -p crashes --check`
- `cargo nextest run -p crashes`

Release Notes:

- Fixed Windows processes remaining alive after a background thread
panic.