Use 'new' expression in places where the type is evident for content (#2590)

* Content.Client

* Content.Benchmarks

* Content.IntegrationTests

* Content.Server

* Content.Server.Database

* Content.Shared

* Content.Tests

* Merge fixes

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Content.Server/GameObjects/Components/Radio/HandheldRadioComponent.cs

@@ -27,7 +27,7 @@ namespace Content.Server.GameObjects.Components.Radio
         private RadioSystem _radioSystem = default!;
 
         private bool _radioOn;
-        private List<int> _channels = new List<int>();
+        private List<int> _channels = new();
 
         [ViewVariables(VVAccess.ReadWrite)]
         private int BroadcastFrequency { get; set; }