Update Rust dependencies and vendor protoc

[xianzuyang9-blip]

This PR updates outdated Rust dependencies for issue #44 and adds a small build-script improvement so protoc is available through protoc-bin-vendored.

Scope:

• Refreshed compatible dependency versions in Cargo.lock.
• Added protoc-bin-vendored = "3" as a build dependency.
• Set PROTOC from the vendored protoc path in build.rs.
• Avoided unrelated source changes.

Verification:

• cargo test --all-features --workspace
• cargo fmt --check
• cargo clippy --all-features --workspace -- -D warnings

Please let me know if you want this narrowed to lockfile-only or expanded to manifest version bumps.

[xianzuyang9-blip]

Thanks! This PR is for #44 and the Tailcall Algora bounty.

Local verification passed before submission:

• cargo test --all-features --workspace
• cargo fmt --check
• cargo clippy --all-features --workspace -- -D warnings

Could a maintainer please approve the first-time-contributor workflow run when convenient?

/claim #44