Repeat how-to-find-proper-argocd-version instructions

docs/admin/installation.rst

@@ -60,6 +60,8 @@ These can be run repeatedly to reinstall Phalanx over an existing deployment.
 
    * If you get a message indicating that ``argocd`` plaintext login has failed, the actual error is that your local ``argocd`` executable is obsolete.
      Update ``argocd`` and try again.
+     To see the version of the client that is currently tested, search for ``argocd-linux`` in `.github/workflows/ci.yaml <https://github.com/lsst-sqre/phalanx/blob/main/.github/workflows/ci.yaml>`__.
+
 
 Using a Vault token rather than AppRole
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