Add .git to .dockerignore

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improved Docker build context by including .git directory.

📊 Key Changes

• Modified .dockerignore to stop ignoring the .git directory.

🎯 Purpose & Impact

• Purpose: This change allows the .git directory to be included in the Docker build context, enabling operations that may depend on Git metadata or history.
• Impact: Users who build Docker images from this repository may notice a slight increase in the build context size, potentially leading to marginally longer image build times. On the positive side, this enables more advanced use-cases where Git information within the Docker container is necessary, such as versioning or continuous integration tasks.