Refactor/remove unused deps and clones

[Himess]

Summary

This PR removes unused dependencies and eliminates redundant clone operations across the codebase, improving build times and runtime performance.

Changes

kms-connector:

• serial_test from connector-utils (dev-dependency)

fhevm-engine/stress-test-generator:

• aws-sdk-s3, humantime, regex, scheduler, semver, serial_test, test-harness, testcontainers, tfhe-worker, tonic-build, zkproof-worker

fhevm-engine/tfhe-worker:

• actix-web, tonic-health, tonic-types, tonic-web

Redundant Clones Removed (11 total)

• fhevm-engine-common: 4 unnecessary .clone() calls
• scheduler: 3 unnecessary .clone() calls
• gw-listener: 3 unnecessary .to_owned() calls
• kms-worker: 1 unnecessary .to_string() call

Testing

[rudy-6-4]

Hi,
Thanks for improving the code base.
Can you activate clippy::redundant_clone so your work set the bar for everybody after and there is no regression ?
https://github.com/zama-ai/fhevm/blob/main/.github/workflows/coprocessor-cargo-clippy.yml#L85
Adding cargo-udeps maybe more complicated but if easy you can add it or share the commands you use so we add it quickly.

I am launching the workflows.

[rudy-6-4]

LGTM, waiting workflow execution to approve

[rudy-6-4]

Note that you need to resolve the conflicts to be able to run the github workflows.

[Himess]

Hi, thanks for the review! @rudy-6-4
Sure , I will enable clippy::redundant_clone and also check cargo-udeps.
I will resolve the conflicts and fix the failing workflows as soon as I'm available.

[Himess]

@rudy-6-4

I've enabled clippy::redundant_clone in the CI workflow as requested. ✅

I've also resolved the merge conflicts with upstream/main. Could you please re-run the workflows when you have a chance?

For finding all clone-related issues locally, I used:

cargo clippy --all-targets -- -W clippy::redundant_clone -W clippy::clone_on_copy -W clippy::unnecessary_to_owned

And for unused dependencies:

cargo +nightly udeps --all-targets

If you'd like to add cargo-udeps to CI or enable additional clippy lints, I'm happy to help - just let me know!

[Himess]

@rudy-6-4
Updated Cargo.lock after dependency removals.
Converting to draft temporarily - found a compilation issue after merging with main (upstream changed MetaParameters struct). Will fix and mark as ready for review shortly.