@greptileai review this draft

Greptile Summary

Removes the protoc installation step from CI and release workflows. This is a valid cleanup since the repository has no .proto files or build.rs file - the Protocol Buffers types come pre-compiled from the s2-sdk and s2-api crates on crates.io.

• Removed arduino/setup-protoc@v3 action from both test and lint jobs in ci.yml
• Removed arduino/setup-protoc@v3 action from build_binaries job in release.yml
• No issues found - this should reduce CI time and simplify the build pipeline

Confidence Score: 5/5

• This PR is safe to merge - it removes an unnecessary build dependency that was never used.
• The protoc compiler was installed but never invoked. There are no .proto files or build.rs scripts in this repository. The prost dependency comes pre-compiled from s2-sdk/s2-api crates, so protoc is not needed at build time.
• No files require special attention.

Important Files Changed

Sequence Diagram

sequenceDiagram
    participant Dev as Developer
    participant CI as CI Workflow
    participant Cargo as Cargo Build
    participant Crates as crates.io

    Dev->>CI: Push/PR
    CI->>CI: Checkout code
    CI->>CI: Install Rust toolchain
    Note over CI: protoc step removed
    CI->>Cargo: cargo build/test
    Cargo->>Crates: Fetch s2-sdk (pre-compiled)
    Crates-->>Cargo: Return crate with prost types
    Cargo-->>CI: Build successful
    CI-->>Dev: CI passed