3.0 release tracking

[Sergio0694]

This issue tracks all changes for the upcoming 3.0 major release.

Features and changes

• Target .NET 8
• Remove all downlevel TFMs
• Introduce IComputeShaderDescriptor<T> API (like with D2D1 shaders)
• Make dispatch threads mandatory for DX12 compute shaders
• GloballyCoherentAttribute for StructuredBuffers  #588
• typeof(T).GUID calls are rooting ~300 KB worth of reflection stuff #551
• Add diagnostic for invalid linking compile option #462
• Use static abstracts in interfaces for all descriptor interfaces
• Add support for primary constructors in all shader types
• Add support for primary constructors for resource types
• Switch DX12 generator to use IndentedTextWriter

Breaking changes

• Remove [AutoConstructor] and generator
• Remove [ShaderMethod] and generator (and infrastructure)