Redesign the Ractor/Knucleotide benchmark #1558

Job	Run time
test (ruby)	1m 14s
benchmark-ractor (head)	6m 52s
test (head)	50s
benchmark-default (head)	11m 7s
benchmark-default (ruby)	11m 1s
benchmark-default (truffleruby)	13m 45s
test (truffleruby)	58s
benchmark-ractor-only (head)	38s
benchmark-run-once	1m 24s
benchmark-graph	49s
all-tests	2s
	48m 40s

Provide feedback