renovate: add annotation to gitlab-runner Dockerfile

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

Author: Adphi

gitlab-runner.Dockerfile

@@ -1,3 +1,7 @@
+# renovate: datasource=gitlab-tags depName=gitlab-org/gitlab-runner versioning=semver
+ARG GITLAB_RUNNER_VERSION=v16.8.0
+ARG GITLAB_RUNNER_IMAGE=gitlab/gitlab-runner:alpine-${GITLAB_RUNNER_VERSION}
+
 FROM golang:alpine
 
 WORKDIR /docker-machine-driver-scaleway
@@ -23,8 +27,7 @@ ARG DOCKER_MACHINE_VERSION=v0.16.2-gitlab.21
 RUN git clone --branch=${DOCKER_MACHINE_VERSION}  https://gitlab.com/gitlab-org/ci-cd/docker-machine .
 RUN CGO_ENABLED=0 GO111MODULE=off go build -o docker-machine -trimpath -ldflags="-s -w" ./cmd/docker-machine
 
-
-FROM gitlab/gitlab-runner:alpine-v16.8.0
+FROM ${GITLAB_RUNNER_IMAGE}
 
 COPY --from=0 /docker-machine-driver-scaleway/docker-machine-driver-scaleway /usr/local/bin/docker-machine-driver-scaleway-v2
 COPY --from=1 /go/src/github.com/docker/machine/docker-machine /usr/local/bin/docker-machine