Review "only unlock once per block" requirement #2
Description
Nodes can unlock the system either via the router entrypoint or via signatures in the before swap hook.
Do we really need to revert after the first one? If the system is unlocked, anyone can swap through the pools. Why should we revert when the nodes try to swap a second time?
See https://github.com/balancer/angstrom-router/blob/a6aeab77e387febce85169fb76ffdd25ca609864/contracts/AngstromRouter.sol#L198 for reference.