Address copilot comments

Author: britneywwc

webapp/app.py

@@ -1134,7 +1134,7 @@ def allow_src(tag, name, value):
         api=DiscourseAPI(
             base_url="https://discourse.dqlite.io/",
             session=discourse_session,
-            cache=ubuntu_discourse_cache,
+            cache=None,
         ),
         index_topic_id=34,
         url_prefix="/dqlite/docs",

webapp/utils/constants.py

@@ -6,5 +6,5 @@
 # it can be hidden on the Candidate Dash.
 SECOND_LOOK_REQ_ID = 3013911
 
-# Default time-to-live for ResponseCache instances, in seconds (24 hours)
+# Default time-to-live for ResponseCache instances, in seconds (1 hour)
 CACHE_TTL = 60 * 60