Manually patch qless lua scripts to work with Redis 6.2.7

More context:
- [qless fix](ledgetech/lua-resty-qless#14)
- [redis 6.2.7 breaking
  change](redis/redis#10651)

I did not regenerate the files from qless-core using the `make`
instructions from the README.md because the commit we have been using
[^1] dates back to Aug 2017, and the same fix has not been applied to
seomoz/qless-core yet. See [^2]

[^1]: seomoz/qless-core@36199bf

[^2]: seomoz/qless-core#90

lib/qless/lua/qless-lib.lua

@@ -33,9 +33,9 @@ QlessRecurringJob.__index = QlessRecurringJob
 Qless.config = {}
 
 -- Extend a table. This comes up quite frequently
-function table.extend(self, other)
+local function extend_table(target, other)
   for i, v in ipairs(other) do
-    table.insert(self, v)
+    table.insert(target, v)
   end
 end
 
@@ -1522,7 +1522,7 @@ function QlessQueue:peek(now, count)
 
   -- With these in place, we can expand this list of jids based on the work
   -- queue itself and the priorities therein
-  table.extend(jids, self.work.peek(count - #jids))
+  extend_table(jids, self.work.peek(count - #jids))
 
   return jids
 end
@@ -1597,7 +1597,7 @@ function QlessQueue:pop(now, worker, count)
 
   -- With these in place, we can expand this list of jids based on the work
   -- queue itself and the priorities therein
-  table.extend(jids, self.work.peek(count - #jids))
+  extend_table(jids, self.work.peek(count - #jids))
 
   local state
   for index, jid in ipairs(jids) do

lib/qless/lua/qless.lua

@@ -24,9 +24,9 @@ QlessRecurringJob.__index = QlessRecurringJob
 
 Qless.config = {}
 
-function table.extend(self, other)
+local function extend_table(target, other)
   for i, v in ipairs(other) do
-    table.insert(self, v)
+    table.insert(target, v)
   end
 end
 
@@ -1118,7 +1118,7 @@ function QlessQueue:peek(now, count)
 
   self:check_scheduled(now, count - #jids)
 
-  table.extend(jids, self.work.peek(count - #jids))
+  extend_table(jids, self.work.peek(count - #jids))
 
   return jids
 end
@@ -1167,7 +1167,7 @@ function QlessQueue:pop(now, worker, count)
 
   self:check_scheduled(now, count - #jids)
 
-  table.extend(jids, self.work.peek(count - #jids))
+  extend_table(jids, self.work.peek(count - #jids))
 
   local state
   for index, jid in ipairs(jids) do