Allow sabotages by dead impostors

2021.12.8+ sets the role of dead players to {Crewmate,Impostor}Ghost, so
relax the anticheat to allow sabotages by ImpostorGhosts

src/Impostor.Api/Innersloth/RoleTypes.cs

@@ -8,5 +8,7 @@ namespace Impostor.Api.Innersloth
         Engineer,
         GuardianAngel,
         Shapeshifter,
+        CrewmateGhost,
+        ImpostorGhost,
     }
 }

src/Impostor.Server/Net/Inner/Objects/InnerPlayerInfo.cs

@@ -34,7 +34,7 @@ namespace Impostor.Server.Net.Inner.Objects
 
         public bool Disconnected { get; internal set; }
 
-        public bool IsImpostor => RoleType is RoleTypes.Impostor or RoleTypes.Shapeshifter;
+        public bool IsImpostor => RoleType is RoleTypes.Impostor or RoleTypes.Shapeshifter or RoleTypes.ImpostorGhost;
 
         public bool CanVent => RoleType is RoleTypes.Impostor or RoleTypes.Shapeshifter or RoleTypes.Engineer;