docs: Upgrade Docker guide to use Ninja

[misterhackerman]

Summary

Updates the build_with_msvc6_on_docker.md guide to utilize modern build tools and LTS package sources.

Key Changes

1. Build System: Switched from NMake to Ninja.
   • Downloads ninja-win.zip.
   • Configures CMake with -G "Ninja".
   • Benefit: Enables multi-threaded compilation (much faster builds).
2. OS Compatibility: Updated WineHQ apt sources to noble (Ubuntu 24.04) to ensure compatibility with the LTS base image.
3. Best Practices: Converted CMD to exec form (["tail", ...]) for better process handling.

[misterhackerman]

solves #76