Drop cancellation at the kill boundary because killing starts
irreversible task and cleanup work that must finish after request
cancellation.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
The container API supports a negative StopTimeout, conventionally -1, to
wait indefinitely without forcefully terminating the container.
The delayed-exit path passed this value to context.WithTimeout, which
expired immediately and triggered fallback exit handling before the real
exit event could be processed.
Use a cancel-only context for negative timeouts so this path preserves
the existing API contract.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
