CA2009 should not be raised when changing the generic type

[andrewimcclement]

Analyzer

Diagnostic ID: CA2009: Do not call ToImmutableCollection on an ImmutableCollection value

Analyzer source

NuGet Package: Microsoft.CodeAnalysis.NetAnalyzers

Version: 8.0.0

Describe the bug

CA2009 should not be raised when changing the generic type, i.e. ImmutableList<T1>.ToImmutableList<T2>() should be valid.

Steps To Reproduce

public interface IFoo {}
public class Foo : IFoo {}

public static class Program
{
    public static void Main()
    {
        var foo = new Foo();
        var list1 = ImmutableList.Create(foo);
        var list2 = list1.ToImmutableList<IFoo>(); // Generates CA2009
    }
}

Expected behavior

CA2009 should only trigger if the generic types are identical.

Actual behavior

CA2009 triggers even if the generic type is different.

Additional context

This is relevant when passing immutable collections to APIs that you do not control (obviously if I were creating list2 to pass in to a method taking IReadOnlyList<IFoo>, passing list1 directly would be fine).