rollup/node: remove batcher simulation

Context

The rollup node batcher simulates all produces batches but it is not really useful as the simuation can't invalidate message. The rollup node is generic and can't know if a specific message is intended for the rollup kernel.

Manually testing the MR

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR