Title: BaseExpressionTypeClauseSyntax appears in official docs but is no longer part of Roslyn (4.13.0)

### Type of issue

Other (describe below)

### Description

The CSharpSyntaxNode documentation page lists BaseExpressionTypeClauseSyntax as a derived type. However, this type no longer exists in Roslyn as of version 4.0+ and is not present in the Roslyn repo source for 4.13.0.
It appears to be a legacy or experimental syntax node that was removed, but it still shows up in API documentation—possibly due to outdated metadata or automated doc generation.
Steps to reproduce:
- Open the CSharpSyntaxNode documentation
- Scroll to the “Derived” section
- Observe that BaseExpressionTypeClauseSyntax is listed
Expected behavior: That type should not appear in the current API docs for Roslyn 4.13.0, as it is no longer valid.
Additional context: This issue may lead to confusion for developers relying on the documentation for analyzer or generator development.

### Page URL

https://learn.microsoft.com/zh-tw/dotnet/api/microsoft.codeanalysis.csharp.csharpsyntaxnode?view=roslyn-dotnet-4.13.0

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