fix perlin noise returns null on some rarte cases as reported in minetest

* i was first checked at https://forum.minetest.net/viewtopic.php?t=8157
  as "minetest.get_perlin() and minetest.get_perlin_map() Return nil" by prestidigitator
  The `minetest.get_perlin()` function returns nil since 0.4.8+ until 5.1.0
  The `PerlinNoise()` constructor does return a valid object, on the other hand,
  barely documented as alternatrive cos is internally used only and not api public
  cos can only call it after the environment is created, so the code
  must bne inside `minetest.after(0, ...)` it only works the first time,
  or must be used an alternative
* was reported also https://github.com/minetest/minetest/issues/10385 that
  does not properly handle large world seeds
* Close https://codeberg.org/Wuzzy/minetest_tsm_pyramids/issues/2
* Close https://codeberg.org/minetest-stuffs/minetest-mod-tsm_pyramids/issues/2
* Also uses older get2d vs get_2d for newer engines older pre 5.0.0
  as seen on https://github.com/minetest-LOTR/Lord-of-the-Test/issues/139
  detect newer engine and uses proper method to get agains perlin object
  Closes https://codeberg.org/minetest-stuffs/minetest-mod-tsm_pyramids/issues/2

init.lua

@@ -38,7 +38,7 @@ local is_50 = minetest.has_feature("object_use_texture_alpha")
 tsm_pyramids = {}
 tsm_pyramids.is_50 = is_50
 tsm_pyramids.S = S
-tsm_pyramids.perlin1 -- perlin noise buffer, make it global cos we need to acess in 5.0 after load all the rest of mods
+tsm_pyramids.perlin1 = nil -- perlin noise buffer, make it global cos we need to acess in 5.0 after load all the rest of mods
 
 dofile(minetest.get_modpath(modpath).."/mummy.lua")
 dofile(minetest.get_modpath(modpath).."/nodes.lua")
@@ -273,6 +273,12 @@ local perl1
 -- if mg v6 set this   {SEED1 = 9130, OCTA1 = 3,       PERS1 = 0.5, SCAL1 = 250} -- Values should match minetest mapgen V6 desert noise.
 perl1 = { SEED1 = 9130, OCTA1 = 1, PERS1 = 0.5, SCAL1 =  25 } -- Values should match minetest mapgen V7 desert noise.
 
+if tsm_pyramids.is_50 then
+	tsm_pyramids.perlin1 = minetest.get_perlin(perl1.SEED1, perl1.OCTA1, perl1.PERS1, perl1.SCAL1)
+else
+	tsm_pyramids.perlin1 = PerlinNoise(perl1.SEED1, perl1.OCTA1, perl1.PERS1, perl1.SCAL1)
+end
+
 local function hlp_fnct(pos, name)
 	local n = minetest.get_node_or_nil(pos)
 	if n and n.name and n.name == name then
@@ -281,6 +287,7 @@ local function hlp_fnct(pos, name)
 		return false
 	end
 end
+
 local function ground(pos, old)
 	local p2 = table.copy(pos)
 	while hlp_fnct(p2, "air") do
@@ -361,12 +368,18 @@ minetest.register_on_generated(function(minp, maxp, seed)
 		return pos
 	end
 
-	if tsm_pyramids.perlin1 == nil then 
+	local noise1 = nil
+	if not tsm_pyramids.perlin1 or tsm_pyramids.perlin1 == nil then
+		if tsm_pyramids.is_50 then
 			tsm_pyramids.perlin1 = minetest.get_perlin(perl1.SEED1, perl1.OCTA1, perl1.PERS1, perl1.SCAL1)
+			noise1 = tsm_pyramids.perlin1:get_2d({x=minp.x,y=minp.y})
+		else
+			tsm_pyramids.perlin1 = PerlinNoise(perl1.SEED1, perl1.OCTA1, perl1.PERS1, perl1.SCAL1)
+			noise1 = tsm_pyramids.perlin1:get2d({x=minp.x,y=minp.y})
 		end
-	local noise1 = tsm_pyramids.perlin1:get_2d({x=minp.x,y=minp.y})
+	end
-	if noise1 == nil then 
+
-		minetest.log("warning", "[tsm_pyramids] canot get 2d noise from perlin buffer---------------------------- ")
+	if not tsm_pyramids.perlin1 or tsm_pyramids.perlin1 == nil or not noise1 or noise1 == nil then
 		return
 	end