swh.loader.pypi.model: Remove dead code

swh/loader/pypi/model.py

@@ -87,9 +87,6 @@ class PyPiProject:
     def author(self, release_name=None):
         return author(self._data(release_name))
 
-    def fetch_release(self, release_name=None):
-        pass
-
     def releases(self):
         # The compute information per release
         releases_dict = self.data['releases']