CA2021 False positive filtering enum of custom type inheriting from Dictionary<U, V> with OfType<T> where T is Dictionary<U, V>

[DavidH541]

Analyzer

Diagnostic ID: CA2021: Don't call Enumerable.Cast<T> or Enumerable.OfType<T> with incompatible types

Analyzer source

SDK: Built-in CA analyzers in .NET 9.0.100-rc.2.24474.11 SDK or later

Version: SDK 9.0.100-rc.2.24474.11

Describe the bug

With classes inherited from Dictionary, OfType generates a warning when filtering an enum with custom Dictionaries on a dictionary with the same types. See example below:

public class CustomDict : Dictionary<int, int>
{
    public string ExtraProp { get; set; } = string.Empty;
}

public class OfTypeWarning
{
    public IEnumerable<CustomDict> customDictEnum = [];

    public void TestOfType()
    {
        var x = customDictEnum.OfType<Dictionary<int, int>>(); <--- this generated CA2021 warning
    }
}

Expected behavior

No warnings

Actual behavior

CA2021 warning