Resolve 'EntitySystem.Get<T>()' is obsolete in content (#27936)

* PROJECT 0 WARNINGS: Resolve `'EntitySystem.Get<T>()' is obsolete` in content

* pass entman

* dog ass test

* webeditor

Content.Server/Atmos/Commands/ShowAtmosCommand.cs

@@ -8,6 +8,8 @@ namespace Content.Server.Atmos.Commands
     [AdminCommand(AdminFlags.Debug)]
     public sealed class ShowAtmos : IConsoleCommand
     {
+        [Dependency] private readonly IEntityManager _e = default!;
+
         public string Command => "showatmos";
         public string Description => "Toggles seeing atmos debug overlay.";
         public string Help => $"Usage: {Command}";
@@ -21,7 +23,7 @@ namespace Content.Server.Atmos.Commands
                 return;
             }
 
-            var atmosDebug = EntitySystem.Get<AtmosDebugOverlaySystem>();
+            var atmosDebug = _e.System<AtmosDebugOverlaySystem>();
             var enabled = atmosDebug.ToggleObserver(player);
 
             shell.WriteLine(enabled