query: make get_latest_tag() always return a list

When rc=True the reversed() iterator is non-subscriptable, breaking the
sorted_tags[-1] fallback path; wrap it in list() to make it indexable.

Signed-off-by: Thomas Perrot <thomas.perrot@bootlin.com>

elixir/query.py

@@ -187,7 +187,7 @@ class Query:
     # This excludes release candidates if `rc` is False.
     def get_latest_tag(self, rc):
         if rc:
-            sorted_tags = reversed(self.scriptLines('list-tags'))
+            sorted_tags = list(reversed(self.scriptLines('list-tags')))
         else:
             sorted_tags = self.scriptLines('get-latest-tags')