kaniko: don't use multiple layers

1 job for master in 24 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
failed #241198
build

00:00:24

 
Name Stage Failure
failed
build Build
CI_JOB_NAME=build
Changed images: ' videolan-kaniko'
make: Entering directory '/builds/videolan/docker-images-aarch64/videolan-kaniko'
docker build -t videolan-kaniko-aarch64:f2b0c82 .
Sending build context to Docker daemon 4.096kB
Error response from daemon: Dockerfile parse error line 20: unknown instruction: CD
make: *** [../common.mak:11: build] Error 1
make: Leaving directory '/builds/videolan/docker-images-aarch64/videolan-kaniko'
ERROR: Job failed: exit code 2