Seal/abstract/virtual everything (#6739)

Content.Shared/Chemistry/MetabolismMovespeedModifierSystem.cs

@@ -12,7 +12,7 @@ using static Content.Shared.Chemistry.Components.MovespeedModifierMetabolismComp
 namespace Content.Shared.Chemistry
 {
     // TODO CONVERT THIS TO A STATUS EFFECT!!!!!!!!!!!!!!!!!!!!!!!!
-    public class MetabolismMovespeedModifierSystem : EntitySystem
+    public sealed class MetabolismMovespeedModifierSystem : EntitySystem
     {
         [Dependency] private readonly IGameTiming _gameTiming = default!;
         [Dependency] private readonly MovementSpeedModifierSystem _movespeed = default!;