[worlds/special_caves] Remove crystal lanterns from the Icy Cave

mods/pyutest/pyutest_mapgen/worlds.lua

@@ -34,6 +34,7 @@ PyuTest.register_world = function (options)
         y_max = conf.y_max,
         y_min = conf.y_min,
         node_water = "air",
+        node_river_water = "air",
         node_cave_liquid = "air",
         vertical_blend = 5
       }))
@@ -73,14 +74,3 @@ SpecialCaveWorld.register_ore({
   biomes = {icy_cave},
   noise_params = PyuTest.SPECIALSTONE_NOISE_PARAMS
 })
-
-SpecialCaveWorld.register_ore({
-  ore_type = "blob",
-  ore = "pyutest_core:crystal_lantern_block",
-  wherein = "pyutest_core:ice_block",
-  clust_scarcity = 5 * 5 * 5,
-  clust_num_ores = 4,
-  clust_size = 5,
-  biomes = {icy_cave},
-  noise_params = PyuTest.SPECIALSTONE_NOISE_PARAMS
-})