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/UserInterface/HumanoidProfileEditor.cs

@@ -25,7 +25,7 @@ namespace Content.Client.UserInterface
 {
     public partial class HumanoidProfileEditor : Control
     {
-        private static readonly StyleBoxFlat HighlightedStyle = new StyleBoxFlat
+        private static readonly StyleBoxFlat HighlightedStyle = new()
         {
             BackgroundColor = new Color(47, 47, 53),
             ContentMarginTopOverride = 10,