Remove circleci configuration

CircleCI is no longer used for CI. For some time it has been a no-op

Signed-off-by: Matt Farina <matt.farina@suse.com>

.circleci/config.yml

@@ -1,14 +0,0 @@
----
-
-# This file can be removed when Helm no longer uses CircleCI on any release
-# branches. Once CircleCI is turned off this file can be removed.
-version: 2
-
-jobs:
-  build:
-    docker:
-      - image: cimg/go:1.18
-
-    steps:
-      - checkout
-