remove @staticmethod decorators

There might have been a time when calling a static method was faster
than a regular method, but that is no longer the case. According to
micro-benchmarks, it is 70% slower in CPython 3.13 and it also makes
executing the code of a class definition slower.

gallery_dl/extractor/naverwebtoon.py

@@ -54,8 +54,7 @@ class NaverwebtoonEpisodeExtractor(NaverwebtoonBase, GalleryExtractor):
                 extr('"painters":[', ']'), '"name":"', '"')]
         }
 
-    @staticmethod
-    def images(page):
+    def images(self, page):
         view_area = text.extr(page, 'id="comic_view_area"', '</div>')
         return [
             (url, None)