Content changes for mapgrid kill (#12567)

Content.IntegrationTests/Tests/PrototypeSaveTest.cs

@@ -8,6 +8,7 @@ using NUnit.Framework;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
+using Robust.Shared.Map.Components;
 using Robust.Shared.Physics;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization.Manager;
@@ -87,7 +88,7 @@ public sealed class PrototypeSaveTest
         var compFact = server.ResolveDependency<IComponentFactory>();
 
         var prototypes = new List<EntityPrototype>();
-        IMapGrid grid = default!;
+        MapGridComponent grid = default!;
         EntityUid uid;
         MapId mapId = default;