How to login to ArgoCD CLI non-interactive in CI like GitHub Actions?

Question

We have a full-blown setup using AWS EKS with Tekton installed and want to use ArgoCD for application deployment.

As the docs state we installed ArgoCD on EKS in GitHub Actions with:

  - name: Install ArgoCD
    run: |
      echo "--- Create argo namespace and install it"
      kubectl create namespace argocd --dry-run=client -o yaml | kubectl apply -f -
      kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

We also exposed the ArgoCD server (incl. dashboard) as the docs told us:

  - name: Expose ArgoCD Dashboard
    run: |
      echo "--- Expose ArgoCD Dashboard via K8s Service"
      kubectl patch svc argocd-server -n argocd -p '{"spec": {"type": "LoadBalancer"}}'

      echo "--- Wait until Loadbalancer url is present (see https://stackoverflow.com/a/70108500/4964553)"
      until kubectl get service/argocd-server -n argocd --output=jsonpath='{.status.loadBalancer}' | grep "ingress"; do : ; done

Finally we installed argocd CLI with brew:

      echo "--- Install ArgoCD CLI"
      brew install argocd

Now how can we do a argocd login with GitHub Actions (without human interaction)? The argocd login command wants a username and password...