Cleanup unused/redundant dependencies (#38099)

Content.Server/Gateway/Systems/GatewayGeneratorSystem.cs

@@ -25,7 +25,6 @@ public sealed class GatewayGeneratorSystem : EntitySystem
 {
     [Dependency] private readonly IConfigurationManager _cfgManager = default!;
     [Dependency] private readonly IGameTiming _timing = default!;
-    [Dependency] private readonly IMapManager _mapManager = default!;
     [Dependency] private readonly IPrototypeManager _protoManager = default!;
     [Dependency] private readonly IRobustRandom _random = default!;
     [Dependency] private readonly ITileDefinitionManager _tileDefManager = default!;