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/comicvine.py

@@ -59,8 +59,7 @@ class ComicvineTagExtractor(BooruExtractor):
 
     _file_url = operator.itemgetter("original")
 
-    @staticmethod
-    def _prepare(post):
+    def _prepare(self, post):
         post["date"] = text.parse_datetime(
             post["dateCreated"], "%a, %b %d %Y")
         post["tags"] = [tag["name"] for tag in post["tags"] if tag["name"]]