fix(hint): make sure to only show hint once (#336)

Signed-off-by: Aaron Pham <contact@aarnphm.xyz>

lua/avante/sidebar.lua

@@ -1008,6 +1008,8 @@ function Sidebar:create_selected_code()
   end
 end
 
+local hint_window = nil
+
 function Sidebar:create_input()
   if self.input then
     self.input:unmount()
@@ -1228,8 +1230,6 @@ function Sidebar:create_input()
     end,
   })
 
-  local hint_window = nil
-
   -- Close the floating window
   local function close_hint()
     if hint_window and api.nvim_win_is_valid(hint_window) then