Confine Dockerfile COPY sources to the build context

Daytona 0.216.0 restricts Dockerfile COPY sources to the build context in the Python, Ruby, and TypeScript SDKs.

Fixes

Python SDK, Ruby SDK, TypeScript SDK: confine COPY sources to the build context

Chores

sync go.sum for v0.215.0

Go SDK: bump to v0.216.0