node:http: make closeAllConnections()/closeIdleConnections() leave the listener alone and work after close() - #35839

Node.js's `closeIdleConnections()` skips on `socket._httpMessage && !socket._httpMessage.finished`, so a socket whose response has `finished === true` (set synchronously by `res.end()`) is treated as idle and destroyed; this predicate checks only truthy `socket._httpMessage`, so a socket in the one-tick window between `res.end()` and the deferred `detachSocket` is spared. The divergence is conservative and the canonical `close(); setTimeout(closeIdleConnections, grace)` pattern never hits it, bu