tests: set appropriate default for validators in test fixtures

[tcoratger]

See

leanSpec/packages/testing/src/consensus_testing/genesis.py

Lines 24 to 27 in b091ef7

	# If validators not provided, create a default set of 4 validators with dummy pubkeys
	# TODO: Set an appropriate default here for test fixtures
	if "validators" not in kwargs:
	validators = Validators(data=[Validator(pubkey=Bytes52.zero()) for _ in range(4)])

or

leanSpec/tests/consensus/devnet/stf_examples/test_invalid.py

Line 22 in b091ef7

validators = Validators(data=[Validator(pubkey=Bytes52.zero()) for _ in range(4)])

We need to define an appropriate default configuration for this.

Related #76 (comment)

[Kayden-ML]

@unnawut @tcoratger Picking this up

[unnawut]

Chiming in on the actual value, in theory I think 3 is the minimum default we need for most test scenarios: 3/3 validators for ideal consensus, 2/3 to test fault tolerance scenarios, 1/3 to test failures.

For more complex cases we'll just need to override the setup like we do here, and I don't think we could have a different default number for those.

[tcoratger]

@unnawut This is solved by #219 no?

[unnawut]

Ah I thought this is about figuring out the default number but yes I think the validator prep looks clean enough right now. Sorry @Kayden-ML for overlapping 🙇‍♂️