Refactor is_unavailable functions

Refs. TS-2276

django/thunderstore/repository/models/package.py

@@ -136,14 +136,11 @@ def update_listing(self, has_nsfw_content, categories, community):
         listing.save(update_fields=("has_nsfw_content",))
 
     def is_unavailable(self, community) -> bool:
-        if self.is_effectively_active is False:
+        if not self.is_effectively_active:
             return True
 
         listing = self.get_package_listing(community)
-        if listing is None:
-            return True
-
-        return listing.is_unavailable
+        return listing is None or listing.is_unavailable
 
     @cached_property
     def has_wiki(self) -> bool:

django/thunderstore/repository/models/package_version.py

@@ -191,10 +191,7 @@ def get_page_url(self, community_identifier: str) -> str:
         )
 
     def is_unavailable(self, community) -> bool:
-        unavailable = self.package.is_unavailable(community)
-        if unavailable:
-            return True
-        return self.is_active is False
+        return self.package.is_unavailable(community) or not self.is_active
 
     @cached_property
     def is_removed(self):