ci: more fixes to make renovate own the Dockerfile

Dockerfile

@@ -1,11 +1,11 @@
 FROM quay.io/argoproj/argocd:v2.13.0
 
 # renovate: datasource=github-releases depName=sops packageName=getsops/sops
-ARG SOPS_VERSION="3.9.1"
+ARG SOPS_VERSION=v3.9.1
 # renovate: datasource=github-releases depName=vals packageName=helmfile/vals
-ARG VALS_VERSION="0.37.6"
+ARG VALS_VERSION=v0.37.6
 # renovate: datasource=github-releases depName=helm-secrets packageName=jkroepke/helm-secrets
-ARG HELM_SECRETS_VERSION="4.6.2"
+ARG HELM_SECRETS_VERSION=v4.6.2
 
 ARG ARGOCD_USER_ID="999"
 
@@ -29,11 +29,11 @@ RUN apt-get update && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
 # sops (use via vals!)
-RUN curl -fsSL https://github.com/getsops/sops/releases/download/v${SOPS_VERSION}/sops-v${SOPS_VERSION}.linux.amd64 \
+RUN curl -fsSL https://github.com/getsops/sops/releases/download/${SOPS_VERSION}/sops-${SOPS_VERSION}.linux.amd64 \
     -o /usr/local/bin/sops && chmod +x /usr/local/bin/sops
 
 # vals backend installation
-RUN curl -fsSL https://github.com/helmfile/vals/releases/download/v${VALS_VERSION}/vals_${VALS_VERSION}_linux_amd64.tar.gz \
+RUN curl -fsSL https://github.com/helmfile/vals/releases/download/${VALS_VERSION}/vals_${VALS_VERSION#v}_linux_amd64.tar.gz \
     | tar xzf - -C /usr/local/bin/ vals \
     && chmod +x /usr/local/bin/vals
 
@@ -44,5 +44,5 @@ ADD sa2kubeconfig.sh /usr/local/bin/sa2kubeconfig.sh
 
 USER ${ARGOCD_USER_ID}
 
-RUN helm plugin install --version ${HELM_SECRETS_VERSION} https://github.com/jkroepke/helm-secrets
+RUN helm plugin install --version ${HELM_SECRETS_VERSION#v} https://github.com/jkroepke/helm-secrets
 RUN mkdir -p /home/argocd/.kube && sed -i -e 's/secrets/secrets --evaluate-templates/' "$(helm env HELM_PLUGINS)/helm-secrets/scripts/wrapper/helm.sh"