fix(utils): Only call callback if type(callback) == "function" (#2038)

lua/cmp/utils/event.lua

@@ -44,7 +44,9 @@ end
 ---@param name string
 event.emit = function(self, name, ...)
   for _, callback in ipairs(self.events[name] or {}) do
-    callback(...)
+    if type(callback) == "function" then
+      callback(...)
+    end
   end
 end