[View Complete Diff of Changes](https://github.com/dotnet/fsharp/compare/616530c723b1017697f4b85a3f76432c3b6881e4...e5136907ae7b5db690206fa70559d1b76bbaca72?w=1) - [Error on invalid declarations in type definitions.](https://github.com/dotnet/fsharp/pull/18813) - [Fix nullable types formatting in `FSharpType.Format` and tooltips to include parentheses](https://github.com/dotnet/fsharp/pull/18842) - [TypeMismatchDiagnosticExtendedData: fix expected type calculation](https://github.com/dotnet/fsharp/pull/18851) - [make devcontainer work with unpublished sdks](https://github.com/dotnet/fsharp/pull/18847) - [Cleanup extended giagnostic data](https://github.com/dotnet/fsharp/pull/18854) - [Type checker: use inner expr range in upcast constraints errors](https://github.com/dotnet/fsharp/pull/18850)