Update dependencies: thruster to 0.1.23, simplecov to 1.0.2, solid_cable to 4.0.2

[rsmoke]

This pull request updates the project to use Ruby version 4.0.6 throughout the codebase and documentation. All references to the previous Ruby version (3.3.4 or 4.0.1) have been replaced to ensure consistency for development, deployment, and documentation.

Ruby Version Upgrade:

• Updated the Ruby version in .ruby-version to 4.0.6
• Updated the Ruby version in .tool-versions to 4.0.6
• Updated the Ruby version in the Gemfile to 4.0.6
• Changed the default Ruby version used in the Dockerfile to 4.0.6
• Updated the commented Ruby version in config/deploy.yml to 4.0.6

Documentation Updates:

• Updated all references to the Ruby version in README.md to 4.0.6, including badges, technology stack, system dependencies, installation instructions, and prerequisites [1] [2] [3] [4] [5]Align version pins across Gemfile, Docker, and docs.