FIX: Ensure that we shutdown thread pool (#1207)

lib/embeddings/vector.rb

@@ -49,7 +49,7 @@ module DiscourseAi
           .zip(*promised_embeddings)
           .value!
           .each { |e| schema.store(e[:target], e[:embedding], e[:digest]) }
-
+      ensure
         pool.shutdown
         pool.wait_for_termination
       end

lib/sentiment/post_classification.rb

@@ -92,7 +92,7 @@ module DiscourseAi
           .zip(*promised_classifications)
           .value!
           .each { |r| store_classification(r[:target], r[:classification]) }
-
+      ensure
         pool.shutdown
         pool.wait_for_termination
       end