Add a specific Dockerfile for simple k3s

1 job for acides in 7 minutes and 44 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
failed #3371
build

00:07:44

 
Name Stage Failure
failed
build Build
(16/16) Installing socat (1.7.3.4-r0)
Executing busybox-1.31.1-r16.trigger
OK: 14 MiB in 30 packages
INFO[0447] Taking snapshot of full filesystem...
INFO[0448] COPY --from=0 /go/src/github.com/rancher/k3s/dist/artifacts/k3s /go/src/github.com/racher/k3s/package/entrypoint.sh /usr/local/bin/
error building image: error building stage: failed to execute command: resolving src: failed to get relative files: lstat /kaniko/0/go/src/github.com/racher/k3s/package/entrypoint.sh: no such file or directory
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1