Capture exception for Scoring

Previously, an exception was caused by the tubesock gem but not sent to Sentry. This caused errors not to bubble up correctly but rather kill the current thread, leaving the user with a generic "WebSocket connection not established" message.

Probably, this should be removed when updating the WebSocket implementation.

app/controllers/submissions_controller.rb

@@ -248,6 +248,11 @@ class SubmissionsController < ApplicationController
           Rails.logger.debug { "Runner error while scoring submission #{@submission.id}: #{e.message}" }
           @testrun[:passed] = false
           save_testrun_output 'assess'
+        rescue StandardError => e
+          Sentry.capture_exception(e)
+          raise e
+        ensure
+          ActiveRecord::Base.connection_pool.release_connection
         end
       end
     end