Don't pass around unnecessary vectors

[richardpringle]

Explain your changes:

• Manually allocating can potentially side-step a compiler optimization of re-using previous allocations where possible. Also, it's not a good practive to pass in a Vec to a function where all you do with the Vec is call as_slice. A Vec consists of a pointer, a length, and a capacity whereas a slice is only a pointer and a length. Slices should always be prefered when elements aren't being added or removed.

Explain how you tested your changes:

• I'm hoping for CI to do this for me, but we should really add tests to this crate

TODO: Will update after passing CI

Checklist:

• Dependency versions are unchanged
  • Notify Velocity team if dependencies must change in CI
• Modified the current draft of release notes with details on what is completed or incomplete within this project
• Document code purpose, how to use it
  • Mention expected invariants, implicit constraints
• Tests were added for the new behavior
  • Document test purpose, significance of failures
  • Test names should reflect their purpose
• All tests pass (CI will check this if you didn't)
• Serialized types are in stable-versioned modules
• Does this close issues? List them

• Closes #0000

[SanabriaRusso]

!ci-build-me

[richardpringle]

!ci-build-me

[Trivo25]

!ci-build-me

[richardpringle]

Closing in favour of o1-labs/proof-systems#3152 (since the code moved)