Cleanup warnings in PolymorphSystem.Map (#36869)

Fix warnings in PolymorphSystem.Map

Content.Server/Polymorph/Systems/PolymorphSystem.cs

@@ -29,7 +29,7 @@ namespace Content.Server.Polymorph.Systems;
 public sealed partial class PolymorphSystem : EntitySystem
 {
     [Dependency] private readonly IComponentFactory _compFact = default!;
-    [Dependency] private readonly IMapManager _mapManager = default!;
+    [Dependency] private readonly SharedMapSystem _map = default!;
     [Dependency] private readonly IPrototypeManager _proto = default!;
     [Dependency] private readonly IGameTiming _gameTiming = default!;
     [Dependency] private readonly ActionsSystem _actions = default!;