build: do not run browserstack in parallel

* No longer runs BrowserStack in parallel because it causes rate limit exceptions that didn't show up if we just had one tunnel per job.

Author: devversion

.circleci/config.yml

@@ -133,7 +133,6 @@ jobs:
     environment:
       BROWSER_STACK_USERNAME: "angularteam1"
       BROWSER_STACK_ACCESS_KEY: "CaXMeMHD9pr5PHg8N7Jq"
-    parallelism: 2
     steps:
       - *checkout_code
       - *restore_cache