Expand using directives in PublicAPIInstance.cs

Added multiple namespaces to the using directives in PublicAPIInstance.cs, including System.Collections, System.Linq, System.Threading, and others. This change enables access to a broader range of functionality required by the file.

Author: Jack251970

Flow.Launcher/PublicAPIInstance.cs

@@ -1,11 +1,12 @@
-using System;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using System.Net;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;