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/EntitySystems/DoorSystem.cs

@@ -35,7 +35,7 @@ namespace Content.Server.GameObjects.EntitySystems
             AllowAll
         }
 
-        private readonly List<ServerDoorComponent> _activeDoors = new List<ServerDoorComponent>();
+        private readonly List<ServerDoorComponent> _activeDoors = new();
 
         public override void Initialize()
         {