test: increase coverage for repl

Refs: https://coverage.nodejs.org/coverage-7abc7e45b2e17730/lib/internal/repl.js.html#L33

PR-URL: https://github.com/nodejs/node/pull/38559


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>