chore(*): just remove variables that are not needed

src/resty/aws/init.lua

@@ -15,7 +15,7 @@ local tablex = require("pl.tablex")
 local lookup_helper = function(self, key)  -- signature to match __index meta-method
   if type(key) == "string" then
     local lckey = key:lower()
-    for k,v in pairs(self) do
+    for k in pairs(self) do
       if type(k) == "string" and k:lower() == lckey then
         error(("key '%s' not found, did you mean '%s'?"):format(key, k), 2)
       end
@@ -193,7 +193,7 @@ do
   -- @param service service-instance being created; field `aws` is the aws instance,
   -- `config` is the service instance config, `api` the service api.
   function AWS.configureEndpoint(service)
-    for i, key in ipairs(derivedKeys(service)) do
+    for _, key in ipairs(derivedKeys(service)) do
 
       local region_rule_config = aws_config.region.rules[key]  --> contains regions templates
       if type(region_rule_config) == 'string' then

src/resty/aws/request/validate.lua

@@ -441,7 +441,7 @@ local validators do
   local list_checks do
     local function get_length(t)  -- gets length of an array (with holes)
       local size = 0
-      for k,v in pairs(t) do
+      for k in pairs(t) do
         if type(k) ~= "number" then
           return nil, "list contains non-numeric indices"
         end