Add a constraint count test for keccak / sha3

[huitseeker]

We have tests for constraint counts in Nova:
https://github.com/lurk-lab/arecibo/blob/605f89990666cae63ff534245ea701199fe0df82/src/circuit.rs#L462-L502
https://github.com/lurk-lab/arecibo/blob/605f89990666cae63ff534245ea701199fe0df82/src/supernova/circuit.rs#L836
https://github.com/lurk-lab/arecibo/blob/605f89990666cae63ff534245ea701199fe0df82/src/supernova/test.rs#L568

And Lurk:
https://github.com/lurk-lab/lurk-rs/blob/f9f87545a3ffa0cf921fa2557021a7b9040b7ad5/src/lem/eval.rs#L1732

and in Lurk for MemoSet:
https://github.com/lurk-lab/lurk-rs/blob/f9f87545a3ffa0cf921fa2557021a7b9040b7ad5/src/coprocessor/memoset/mod.rs#L791

That count the number of expected constraints in a circuit. We should add one for the recently added keccak/sha3 gadgets (see #14) ideally using expect_test