Revert "repl: refactor tests to not rely on timing"

This reverts commit de848ac1.

The commit broke multiline repl.

PR-URL: https://github.com/nodejs/node/pull/18715
Refs: https://github.com/nodejs/node/pull/17828


Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>