fix antag selection being evil (#28197)

* fix antag selection being evil

* fix test

* untroll the other tests

* remove role timer troll

* Allow tests to modify antag preferences

* Fix antag selection

* Misc test fixes

* Add AntagPreferenceTest

* Fix lazy mistakes

* Test cleanup

* Try stop players in lobbies from being assigned mid-round antags

* ranting

* I am going insane

---------

Co-authored-by: deltanedas <@deltanedas:kde.org>
Co-authored-by: ElectroJr <leonsfriedrich@gmail.com>

Content.Shared/Roles/Jobs/SharedJobSystem.cs

@@ -146,8 +146,10 @@ public abstract class SharedJobSystem : EntitySystem
 
     public bool CanBeAntag(ICommonSession player)
     {
+        // If the player does not have any mind associated with them (e.g., has not spawned in or is in the lobby), then
+        // they are eligible to be given an antag role/entity.
         if (_playerSystem.ContentData(player) is not { Mind: { } mindId })
-            return false;
+            return true;
 
         if (!MindTryGetJob(mindId, out _, out var prototype))
             return true;