System.Configuration.GetSection(String) returns description is incorrect

[rbennett10]

Describe the issue or suggestion

The current returns description of GetSection() indicates that it returns null. That is incorrect.

The specified ConfigurationSection object, or null if the requested section does not exist.

The return type is not marked as nullable in the source code:
https://github.com/dotnet/runtime/blob/main/src/libraries/System.Configuration.ConfigurationManager/src/System/Configuration/Configuration.cs#L165

public ConfigurationSection GetSection(string sectionName)

In the ASP.NET Core docs it correctly states "GetSection never returns null":
https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/fundamentals/configuration/index.md?plain=1#L705

GetSection never returns null. If a matching section isn't found, an empty IConfigurationSection is returned.

The correction should be made here:
https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.Configuration/Configuration.xml#L356

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