Use boss entity as source for obsidian bomb.

Makes the boss entity the source of the obsidian bomb explosion, which
then makes the damage event listener handle the explosion damage as if
the boss is the damager, which means the `monster-infight` flag should
be respected.

Fixes #759

changelog.md

@@ -13,6 +13,7 @@ These changes will (most likely) be included in the next version.
 ## [Unreleased]
 ### Fixed
 - Explosion damage caused by Exploding Sheep now correctly counts as monster damage. This means that the explosions only affect other mobs if the per-arena setting `monster-infight` is set to `true`.
+- Explosion damage caused by the boss ability `obsidian-bomb` now correctly counts as monster damage. This means that the explosions only affect other mobs if the per-arena setting `monster-infight` is set to `true`.
 
 ## [0.107] - 2022-07-30
 ### Added

src/main/java/com/garbagemule/MobArena/waves/ability/core/ObsidianBomb.java

@@ -55,7 +55,7 @@ public class ObsidianBomb implements Ability
                     return;
 
                 world.getBlockAt(loc).setType(Material.AIR);
-                world.createExplosion(loc, 3F);
+                world.createExplosion(loc, 3F, false, true, boss.getEntity());
             }
         }, FUSE);
     }