Circleci: remove unused config (#44136)

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.circleci/config.yml

@@ -1,11 +0,0 @@
-version: 2.1
-jobs:
-  build:
-    docker:
-      - image: alpine:3.7
-    steps:
-      - run:
-          name: The First Step
-          command: |
-            echo 'Fake step!'
-