chore: reduce cycle length for AAC tests

[Jiloc]

Description

The consensus tests currently take 20-30 seconds each to run on my machine, mostly due to the long cycle length of 100 blocks.
The new values are the lowest ones (empirically) accepted. Reducing the running of 4 consensus tests from ~1 min and 45 secs to ~2 seconds.

Only the MARF hashes currently changes from running the same tests. But I may be missing something given @jferrant comments in the code.

Applicable issues

• fixes #

Additional info (benefits, drawbacks, caveats)

Checklist

• Test coverage for new or modified code paths
• Changelog is updated
• Required documentation changes (e.g., docs/rpc/openapi.yaml and rpc-endpoints.md for v2 endpoints, event-dispatcher.md for new events)
• New clarity functions have corresponding PR in clarity-benchmarking repo

[jferrant]

Nope I was debating lowering it myself in my WIP PR myself. I realized in the process that we actually lockup the stx for 12 reward cycles. So as long as we don't exceed that many reward cycles, we don't have to worry about restacking/reregistering signers.