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/GravitySystem.cs

@@ -28,7 +28,7 @@ namespace Content.Server.GameObjects.EntitySystems
 
         private const uint ShakeTimes = 10;
 
-        private Dictionary<GridId, uint> _gridsToShake = new Dictionary<GridId, uint>();
+        private Dictionary<GridId, uint> _gridsToShake = new();
 
         private float _internalTimer = 0.0f;