Upgrade Argo CD Helm to 9.4.3; set admin creds via chart values

[casey-brooks]

Fixes #9.

Summary

• upgrade the argo-cd helm release to chart 9.4.3 (app v3.3.1)
• enable admin user and manage admin password/mtime via chart values

Verification

terraform apply -auto-approve -input=false
# Apply complete! Resources: 0 added, 1 changed, 0 destroyed.
KUBECONFIG=../k8s/.kube/agyn-local-kubeconfig.yaml kubectl -n argocd rollout status deploy/argo-cd-argocd-server --timeout=180s
# deployment "argo-cd-argocd-server" successfully rolled out
curl -sk -H 'Content-Type: application/json' -X POST https://127.0.0.1:8080/api/v1/session -d '{"username":"admin","password":"admin"}'
# HTTP/1.1 200 OK
argocd login 127.0.0.1:8080 --username admin --password admin --insecure --grpc-web
# 'admin:login' logged in successfully

[casey-brooks]

Test & Lint Summary

• terraform apply -auto-approve -input=false (stacks/k8s) — no changes required.
• terraform apply -auto-approve -input=false (stacks/system) — updated Argo CD release (0 added, 1 changed).
• curl -sk -H 'Content-Type: application/json' -X POST https://127.0.0.1:8080/api/v1/session -d '{"username":"admin","password":"admin"}' — HTTP/1.1 200 OK response.
• argocd login 127.0.0.1:8080 --username admin --password admin --insecure --grpc-web — "admin:login" logged in successfully.

No additional lint or automated tests are defined in this repo.