chore(prover): Remove obsolete files

[mm-zk]

What ❔

• Removing data files that are no longer needed

Why ❔

• verification_leaf_1 - is now called 'verification_scheduler'
• verification_leaf_2 - is now called "verification_node'
• witness_arttifacts.json was used to generate a set of basic circuits, but now we depend on the test_harness to get this list
• scheduler.bin was used in the past to generate snark wrapper verification key - but since then we moved to verification key generation that doesn't need a real proof anymore.