remove unused statement and variable

nix_update/update.py

@@ -142,7 +142,6 @@ def update_version(
                 raise UpdateError(
                     "Could not find a url in the derivations src attribute"
                 )
-        version
         if preference != VersionPreference.BRANCH:
             branch = None
         elif version == "branch":

nix_update/version/rubygems.py

@@ -13,7 +13,7 @@ def fetch_rubygem_versions(url: ParseResult) -> List[Version]:
         return []
     parts = url.path.split("/")
     gem = parts[-1]
-    gem_name, rest = gem.rsplit("-")
+    gem_name, _ = gem.rsplit("-")
     versions_url = f"https://rubygems.org/api/v1/versions/{gem_name}.json"
     info(f"fetch {versions_url}")
     resp = urllib.request.urlopen(versions_url)