helm diff should not error with --reuse-values if release doesn't exist

[frankh]

helm diff version: 3.6.0

helm diff upgrade --allow-unreleased release charts/my-chart --namespace stuff --reuse-values
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	Release was not present in Helm.  Diff will show entire contents as new.

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Error: Failed to render chart: exit status 1
Error: plugin "diff" exited with error

running the equivalent helm upgrade command does not error:

helm upgrade release charts/my-chart --namespace stuff --install --reuse-values --dry-run

In fact when using HELM_DIFF_USE_UPGRADE_DRY_RUN the --reuse-values flag should do nothing except pass through the flag to helm upgrade