False positive CA2012 with extension block

[andryushchenko]

Describe the bug

False positive CA2012 for ValueTask extensions when using extension block. No warnings for classic extension method or when calling as static method.

To Reproduce

Simple code to reproduce with .NET SDK 10.0.101

await ValueTask.FromResult("test").Test1().ConfigureAwait(false); // OK
await ValueTask.FromResult("test").Test2().ConfigureAwait(false); // CA2012
await ExtensionTest.Test2(ValueTask.FromResult("test")).ConfigureAwait(false); //OK

public static class ExtensionTest
{
    public static async ValueTask Test1<T>(this ValueTask<T> valueTask)
    {
        Console.WriteLine(await valueTask.ConfigureAwait(false));
    }
    
    extension<T>(ValueTask<T> valueTask)
    {
        public async ValueTask Test2()
        {
            Console.WriteLine(await valueTask.ConfigureAwait(false));
        }
    }
}

Expected behavior

No warnings