System.Text.Encoding.CodePages giving warning will not be pruned when used with .net version 10

**Version Used**: .net 10

**Steps to Reproduce**:

1. PackageReference Include="System.Text.Encoding.CodePages"
Version="10.0.0"
2. use targetFramework .net version 10
3.

A minimal repro, with source-code provided, is ideal. Most compiler/language issues can be distilled into a snippet that can be pasted into [.NET Lab](https://lab.razor.fyi/#csharp).

**Diagnostic Id**:

If this is a report about a bug in an analyzer, please include the diagnostic ID and message if possible (e.g. `"IDE0030: Use coalesce expression"`).

**Expected Behavior**:should not give error/warning

**Actual Behavior**: PackageReference System.Text.Encoding.CodePages will not be pruned. Consider removing this package from your dependencies, as it is likely unnecessary.

Start by creating the minimal .NET 10 project described in the issue, adding System.Text.Encoding.CodePages version 10.0.0 and targeting .NET 10. Run the project build and observe the package-pruning warning. Done means the package is correctly recognized as necessary or unnecessary without producing the reported incorrect warning.

Written by the indexing model from the issue text.