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.Client/GameObjects/Components/Mobs/ClientAlertsComponent.cs

@@ -45,7 +45,7 @@ namespace Content.Client.GameObjects.Components.Mobs
 
         [ViewVariables]
         private readonly Dictionary<AlertKey, AlertControl> _alertControls
-            = new Dictionary<AlertKey, AlertControl>();
+            = new();
 
         /// <summary>
         /// Allows calculating if we need to act due to this component being controlled by the current mob