drop sound_api global legacy support as not known to be used (#2)

* drop sound_api support as not known to be used

* update .luacheckrc and move some globals over to read

* move one global back in .luacheckrc

.luacheckrc

@@ -4,9 +4,7 @@ allow_defined_top = true
 exclude_files = {".luacheckrc"}
 
 globals = {
-    "minetest", "sound_api", "xcompat", "default",
-    "mcl_sounds", "ks_sounds", "nodes_nature", "fl_stone",
-    "fl_topsoil", "fl_trees", "hades_sounds", "rp_sounds",
+    "minetest", "xcompat",
 }
 
 read_globals = {
@@ -20,5 +18,5 @@ read_globals = {
     "vector", "ItemStack", "dump", "DIR_DELIM", "VoxelArea", "Settings", "PcgRandom", "VoxelManip", "PseudoRandom",
 
     --mod produced
-    "fl_dyes", "fl_hand", "fl_tools", "mobkit", "fl_tnt", "i3",
+    "default", "mcl_sounds", "ks_sounds", "nodes_nature", "fl_stone", "fl_topsoil", "fl_trees", "hades_sounds", "rp_sounds",
 }

init.lua

@@ -5,9 +5,6 @@ xcompat = {
     materials = dofile(modpath .. "/src/materials.lua"),
 }
 
---this exists for legacy compat reasons
-sound_api = xcompat.sounds -- luacheck: ignore
-
 local function validate_sound(key)
     if key and xcompat.sounds[key] then
         return true