Enemy boat bug fix

Changes:
- Fixed an issue where biters around enemy boat would sometimes not attack the player boat.

maps/pirates/ai.lua

@@ -19,6 +19,7 @@ local IslandEnum = require 'maps.pirates.surfaces.islands.island_enum'
 -- local Crew = require 'maps.pirates.crew'
 -- local Quest = require 'maps.pirates.quest'
 local SurfacesCommon = require 'maps.pirates.surfaces.common'
+local Utils = require 'maps.pirates.utils_local'
 
 local Public = {}
 
@@ -895,7 +896,7 @@ function Public.try_boat_biters_attack()
 				Public.send_boat_biters_for_attack(eboat)
 			end
 		else
-			destination.dynamic_data.enemyboats[i] = nil
+			Utils.fast_remove(destination.dynamic_data.enemyboats, i)
 		end
 	end
 end

maps/pirates/api_on_tick.lua

@@ -873,7 +873,7 @@ function Public.boat_movement_tick(tickinterval)
 					do end
 				end
 			else
-				destination.dynamic_data.enemyboats[i] = nil
+				Utils.fast_remove(destination.dynamic_data.enemyboats, i)
 			end
 		end
 	end

maps/pirates/utils_local.lua

@@ -216,6 +216,18 @@ function Public.ordered_table_with_index_removed(tbl, index)
 	return to_keep
 end
 
+-- Implementation of table.fast_remove
+function Public.fast_remove(tbl, index)
+    local count = #tbl
+    if index > count then
+        return
+    elseif index < count then
+        tbl[index] = tbl[count]
+    end
+
+    tbl[count] = nil
+end
+
 function Public.length(tbl)
 	local count = 0
 	for k, _ in pairs(tbl) do