refactor: lookup-less `sign` `relu` `abs` #4201

Job	Run time
build	5m 5s
library-tests	3m 56s
docs	5m 13s
model-serialization	3m 21s
prove-and-verify-aggr-tests-gpu	1m 58s
python-integration-tests	1h 37m 46s
ultra-overflow-tests	10m 18s
ultra-overflow-tests_og-lookup	10m 19s
wasm32-tests	7m 8s
prove-and-verify-tests	2h 40m 29s
python-tests	23m 12s
examples	11m 48s
prove-and-verify-evm-tests	1h 36m 8s
prove-and-verify-mock-aggr-tests	15m 31s
tutorial	14m 56s
accuracy-measurement-tests	43m 47s
mock-proving-tests	3h 1m 32s
prove-and-verify-aggr-evm-tests	37m 7s
prove-and-verify-aggr-tests	40m 7s
	12h 49m 41s

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