fix: update Protocol Buffers metadata to 35.1

[github-actions]

The automated language version check found a pending Protocol Buffers update.

• Language: Protocol Buffers (protobuf)
• Current version: 35.0
• Detected version: 35.1
• Source: https://api.github.com/repos/protocolbuffers/protobuf/releases/latest
• File: src/languages/protobuf.ts

Please verify the upstream source before updating the metadata.