fix: simplify cost table format #110

Job	Run time
basic-operations/anchor/burn	2m 26s
counter/anchor	1m 19s
create-and-update	1m 25s
basic-operations/anchor/update	1m 27s
basic-operations/anchor/create-nullifier	1m 14s
basic-operations/anchor/close	1m 13s
basic-operations/anchor/reinit	1m 14s
basic-operations/anchor/create	1m 9s
	11m 27s

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