[Swift shipping] Create `Swift.Bindings.Experimental` and tooling NuGet packages in the dotnet-experimental feed

[kotlarmilos]

Tasks:

• [Swift bindings] Add bindings experimental NuGet to the dotnet-experimental feed #2878
• [Swift bindings] Upgrade dotnet runtime version to 9.0.0 #2879
• [Swift bindings] Enable real signing of experimental NuGet package #2897
• [Swift Bindings] Ensure projection tooling generate bindings that compile for selected frameworks #2900
• Make the tooling and tests compatible with Windows dev environment Note: MachO reader is Apple-specific.
• Update packaging to bundle generated Swift code

Note

This issue tracks progress and will be expanded with more details. If specific tasks for this issue are not clear, this means that the task is not well defined yet and needs attention.