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/Eui/EuiManager.cs

@@ -15,7 +15,7 @@ namespace Content.Client.Eui
         [Dependency] private readonly IReflectionManager _refl = default!;
         [Dependency] private readonly IDynamicTypeFactory _dtf = default!;
 
-        private readonly Dictionary<uint, EuiData> _openUis = new Dictionary<uint, EuiData>();
+        private readonly Dictionary<uint, EuiData> _openUis = new();
 
         public void Initialize()
         {