remove unused usings in MainViewModel
MODIFY
WalletWasabi.Fluent/ViewModels/MainViewModel.cs
WalletWasabi.Fluent/ViewModels/MainViewModel.cs
#nullable enable
-using Avalonia.Threading;
using NBitcoin;
using ReactiveUI;
using System.Reactive;
-using System.Reactive.Linq;
-using System.Text;
-using System.Threading.Tasks;
using WalletWasabi.Gui.ViewModels;
using WalletWasabi.Fluent.ViewModels.Dialog;
using Global = WalletWasabi.Gui.Global;

remove unused usings in MainViewModel