Remove deprecated registration CLI option

Ref:
https://docs.gitlab.com/ee/update/deprecations.html#registration-tokens-and-server-side-runner-arguments-in-gitlab-runner-register-command

Thanks to @maxsatula for pointing this out.

Fixes #12

Signed-off-by: Chris Evich <cevich@redhat.com>

Containerfile

@@ -65,7 +65,6 @@ LABEL register="podman run -it --rm \
  -e RUNNER_NAME=pipglr \
  -e RUNNER_EXECUTOR=docker \
  -e RUNNER_SHELL=bash \
- -e REGISTER_MAINTENANCE_NOTE=Podman-In-Podman-GitLab-Runner \
  -e DOCKER_HOST=unix:///home/runner/podman.sock \
  -e DOCKER_IMAGE=${DEFAULT_JOB_IMAGE} \
  -e DOCKER_CACHE_DIR=/cache \