fix: Repo URL link for unsupported sources links to https://<argocd>/null/path/to/chart (cherry-pick #14861)#14872

gcp-cherry-pick-bot[bot] wants to merge 0 commit intorelease-2.8argoproj/argo-cd:release-2.8from

cherry-pick-f74e74-release-2.8argoproj/argo-cd:cherry-pick-f74e74-release-2.8Copy head branch name to clipboard