Redesign the Ractor/Knucleotide benchmark #1545

Job	Run time
benchmark-ractor (ruby)	22m 7s
benchmark-ractor (head)	6m 49s
test (truffleruby)	48s
benchmark-default (truffleruby)	16m 11s
benchmark-default (head)	11m 28s
test (head)	56s
benchmark-default (ruby)	11m 2s
benchmark-ractor-only (ruby)	1m 7s
benchmark-ractor-only (head)	36s
test (ruby)	56s
benchmark-graph	53s
benchmark-run-once	1m 27s
all-tests	3s
	1h 14m 23s

Provide feedback