WIP: add virtualized selection benchmarks - #2

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-dotnet@v4, actions/upload-artifact@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Possible null reference argument for parameter 'collection' in 'HashSet<T?>.HashSet(IEnumerable<T?> collection, IEqualityComparer<T?>? comparer)'.

Converting method group 'OnDoubleClick' to non-delegate type 'object'. Did you intend to invoke the method?

Dereference of a possibly null reference.

Possible null reference argument for parameter 'collection' in 'HashSet<T?>.HashSet(IEnumerable<T?> collection, IEqualityComparer<T?>? comparer)'.

Possible null reference argument for parameter 'arg' in 'ICollection<T?> Func<ICollection<T?>, ICollection<T?>>.Invoke(ICollection<T?> arg)'.

Possible null reference argument for parameter 'arg' in 'ICollection<T?> Func<ICollection<T?>, ICollection<T?>>.Invoke(ICollection<T?> arg)'.

Dereference of a possibly null reference.

Nullability of reference types in type of parameter 'sender' of 'void MudWatch.Elapse(object sender, ElapsedEventArgs args)' doesn't match the target delegate 'ElapsedEventHandler' (possibly because of nullability attributes).

The type 'T' cannot be used as type parameter 'TKey' in the generic type or method 'Dictionary<TKey, TValue>'. Nullability of type argument 'T' doesn't match 'notnull' constraint.

The type 'T' cannot be used as type parameter 'TKey' in the generic type or method 'Dictionary<TKey, TValue>'. Nullability of type argument 'T' doesn't match 'notnull' constraint.