refactor: lookup-less `sign` `relu` `abs` #4193

Job	Run time
build	3m 52s
docs	3m 57s
library-tests	3m 42s
model-serialization	3m 14s
prove-and-verify-aggr-tests-gpu	2m 42s
python-integration-tests	3m 58s
ultra-overflow-tests	1s
ultra-overflow-tests_og-lookup	1s
ultra-overflow-tests-gpu	1m 10s
python-tests	1s
examples	1s
prove-and-verify-tests	1s
prove-and-verify-evm-tests	1s
tutorial	1s
mock-proving-tests	1s
wasm32-tests	1s
accuracy-measurement-tests	1s
prove-and-verify-aggr-evm-tests	1s
prove-and-verify-mock-aggr-tests	1s
prove-and-verify-aggr-tests	1s
	22m 48s

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