test: fix flaky test-tls-socket-close

Replace timer/timeout race with event-based ordering, eliminating test
flakiness.

PR-URL: https://github.com/nodejs/node/pull/11921
Fixes: https://github.com/nodejs/node/issues/11912


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>