Fix: fix Dockerfile to add pyproject.toml anchor file

[weijinglin]

This PR fixes both Dockerfile.llm and Dockerfile.nk by adding the missing step to copy pyproject.toml into the runtime image.

Details:

• Added COPY command to include /build/hugegraph-llm/pyproject.toml (or /home/work/hugegraph-llm/pyproject.toml) in the final image.
• Ensures that pyproject.toml is available in the runtime environment for get_project_path() api in anchor.py
• Improves image completeness.