DEV: Remove summarization code (#27373)

plugins/chat/config/locales/client.en.yml

@@ -144,13 +144,6 @@ en:
       join: "Join"
       last_visit: "last visit"
 
-      summarization:
-        title: "Summarize messages"
-        description: "Select an option below to summarize the conversation sent during the desired timeframe."
-        summarize: "Summarize"
-        since:
-          one: "Last hour"
-          other: "Last %{count} hours"
       mention_warning:
         invitations_sent:
           one: "Invitation sent"

plugins/chat/config/locales/server.en.yml

@@ -196,9 +196,6 @@ en:
         one: "and %{count} other"
         other: "and %{count} others"
 
-    summaries:
-      no_targets: "There were no messages during the selected period."
-
     transcript:
       default_thread_title: "Thread"
       split_thread_range: "messages %{start} to %{end} of %{total}"