[misc] fix express deprecations

Co-Authored-By: Jakob Ackermann <jakob.ackermann@overleaf.com>

services/track-changes/app.js

@@ -109,7 +109,7 @@ app.get('/health_check', HttpController.healthCheck)
 
 app.use(function(error, req, res, next) {
   logger.error({ err: error, req }, 'an internal error occured')
-  return res.send(500)
+  return res.sendStatus(500)
 })
 
 const port =