refactor: adjust ordering of weather arts

- Change ordering of previous weather art to use 'id' descending
- Change ordering of next weather art to use 'id' ascending
- Remove unnecessary blank line in seeds file

These changes enhance the consistency of the weather art
navigation by using 'id' for ordering, ensuring the
correct retrieval of records.

app/controllers/weather_arts_controller.rb

@@ -5,12 +5,12 @@ class WeatherArtsController < ApplicationController
 
     @previous_weather_art = @city.weather_arts
                                  .where("id < ?", @weather_art.id)
-                                 .order(weather_date: :desc)
+                                 .order(id: :desc)
                                  .first
 
     @next_weather_art = @city.weather_arts
                              .where("id > ?", @weather_art.id)
-                             .order(weather_date: :asc)
+                             .order(id: :asc)
                              .first
 
     ahoy.track "View Weather Art", {

db/seeds.rb

@@ -204,4 +204,3 @@ guangzhou_weather_art3.image.attach(
   filename: "sample-guangzhou-weather-art-2.png",
   content_type: "image/png"
 )
-