Add comprehensive report of obsolete APIs in AspNetCore.Docs

[Copilot]

Cataloged all APIs marked with [Obsolete] attribute or documented as obsolete in the repository.

Findings

Created OBSOLETE_APIS_REPORT.md documenting 8 obsolete API groups across the ASP.NET Core documentation:

• CompatibilityVersion enum values (Version_2_0, Version_2_1, Version_2_2)
• SpaServices/NodeServices packages (obsolete since 3.0)
• IJSUnmarshalledRuntime interface (obsolete in .NET 7+)
• UseDatabaseErrorPage method
• IHostingEnvironment interface (replaced by IWebHostEnvironment in 3.1)
• SignOutSessionStateManager class (obsolete in .NET 7+)
• RouteContext type (planned for future obsolescence)
• ComplexTypeModelBinderProvider class

Each entry includes:

• Full namespace and type information
• Source file locations with line numbers
• Obsolescence status and affected versions
• Replacement APIs and migration paths

Context

This is a documentation repository containing sample code and markdown files. Search covered 5,883 C# files and all markdown documentation. No [Obsolete] attributes found in sample code; all references are in migration guides and API documentation explaining obsolete features to developers.

Original prompt

Find all API in this repo that have the [Obsolete] attribute that would look like this: [Obsolete("*

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