Revert "fix(radiation): 让玩家在进入是获得辐射免疫 (#907)"

This reverts commit 7f9f9b2.

src/main/java/io/github/thebusybiscuit/slimefun4/implementation/listeners/RadioactivityListener.java

@@ -7,7 +7,6 @@
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.entity.PlayerDeathEvent;
-import org.bukkit.event.player.PlayerJoinEvent;
 
 /**
  * {@link RadioactivityListener} handles radioactivity level resets
@@ -26,10 +25,4 @@ public void onPlayerDeath(@Nonnull PlayerDeathEvent e) {
         RadiationUtils.clearExposure(e.getEntity());
         RadiationTask.addGracePeriod(e.getEntity());
     }
-
-    @EventHandler
-    public void onPlayerJoin(@Nonnull PlayerJoinEvent e) {
-        RadiationUtils.clearExposure(e.getPlayer());
-        RadiationTask.addGracePeriod(e.getPlayer());
-    }
 }