Scoru,Bench: backport "deserialize_output_proof" benchmark

Context

The cost using this model will be back-ported in the final snapshot. We backport the benchmark as well in Mumbai. It should not cause any conflict with the snapshotting process.

Extracts the commits modifying the benchmarks from !7116 (merged) and backport them to Mumbai.

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