Remove redundant #nullable enable (#4275)

Content.Shared/MobState/State/BaseMobState.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects;
 using Robust.Shared.Serialization.Manager.Attributes;
 
 namespace Content.Shared.MobState.State

Content.Shared/MobState/State/IMobState.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using Content.Shared.ActionBlocker;
+using Content.Shared.ActionBlocker;
 using Robust.Shared.GameObjects;
 
 namespace Content.Shared.MobState.State

Content.Shared/MobState/State/SharedCriticalMobState.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using Content.Shared.Alert;
+using Content.Shared.Alert;
 using Content.Shared.Hands;
 using Content.Shared.Standing;
 using Robust.Shared.GameObjects;

Content.Shared/MobState/State/SharedNormalMobState.cs

@@ -1,7 +1,6 @@
 using Content.Shared.Standing;
 using Robust.Shared.GameObjects;
 
-#nullable enable
 
 namespace Content.Shared.MobState.State
 {