CircleCI: Testing upgrade to CircleCI 2.1 (#21374)

.circleci/config.yml

+version: 2.1
+
 aliases:
   # Workflow filters
   - &filter-only-release
@@ -14,8 +16,6 @@ aliases:
     branches:
       only: master
 
-version: 2
-
 jobs:
   mysql-integration-test:
     docker:
@@ -1071,7 +1071,6 @@ jobs:
             - $HOME/.cache/trivy
 
 workflows:
-  version: 2
   build-master:
     jobs:
       - build-all: