feat: refactor Docker container management to use Testcontainers

[glucaci]

This pull request introduces significant changes to the project’s core infrastructure, primarily migrating from Docker.DotNet to the Testcontainers library for managing Docker containers. It also updates CI/CD workflows for improved .NET version support and simplifies the project’s configuration and dependency management. Several obsolete or Docker.DotNet-specific abstractions have been removed, and package references have been updated accordingly.

Migration to Testcontainers and Dependency Updates:

• Replaced the Docker.DotNet.Enhanced dependency with Testcontainers and its related packages (e.g., Testcontainers.MongoDb, Testcontainers.PostgreSql, etc.) in Directory.Packages.props and src/Core/Core.csproj. Also updated SSH.NET and downgraded xunit.runner.visualstudio to resolve compatibility issues. [1] [2] [3] [4]
• Refactored the core container management logic to use TestcontainersDockerManager instead of the previous Docker.DotNet-based manager in ContainerResource.cs.
• Removed Docker.DotNet-specific types and configuration logic, including DockerAuth.cs, DockerConfiguration.cs, and related configuration/resolver code from ContainerResourceOptions.cs, ContainerResourceBuilder.cs, and ContainerResourceSettings.cs. [1] [2] [3] [4] [5] [6] [7] [8]

CI/CD and Build Improvements:

• Enhanced the GitHub Actions CI workflow to test against .NET 8, 9, and 10 using a matrix strategy, added concurrency controls, and improved job naming and timeouts. [1] [2]
• Updated the release workflow to build and pack using the matrix strategy and improved job naming. [1] [2] [3] [4]
• Added a nuget.config to explicitly set the NuGet package source.

Codebase Simplification and Cleanup:

• Refactored ChmodCommand to return simple string arrays for commands instead of Docker.DotNet-specific types, and removed unnecessary imports. [1] [2]
• Cleaned up unused properties and methods related to Docker.DotNet in ContainerInstance.cs and other core files. [1] [2]
• Updated project build logic in all.csproj to align with the new test/build separation and property naming (BuildTestsOnly).

These changes modernize the container management approach, streamline configuration, and improve CI/CD robustness for multi-version .NET testing.

[Carael]

Nice! A little bit sad but for sake of compatibility let's do it!🚀