introduce requirement to prevent from being tasked to steal your own item (#11139)

Content.Server/Objectives/Requirements/NotRoleRequirement.cs

@@ -0,0 +1,25 @@
+using Content.Shared.Roles;
+using Content.Server.Objectives.Interfaces;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype;
+
+namespace Content.Server.Objectives.Requirements
+{
+
+    [DataDefinition]
+    public sealed class NotRoleRequirement : IObjectiveRequirement
+    {
+        [DataField("roleId", customTypeSerializer:typeof(PrototypeIdSerializer<JobPrototype>))]
+        private string roleId = "";
+
+        /// <summary>
+        /// This requirement is met if the traitor is NOT the roleId, and fails if they are.
+        /// </summary>
+        public bool CanBeAssigned(Mind.Mind mind)
+        {
+            if (mind.CurrentJob == null) // no job no problems
+                return true;
+
+            return (mind.CurrentJob.Prototype.ID != roleId);
+        }
+    }
+}