test: fix test-benchmark-streams

test-benchmark-streams is currently failing because the `sync` option is
not specified in the test, resulting in too many benchmarks running.

PR-URL: https://github.com/nodejs/node/pull/30757


Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>