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Please add a summary of your change

TLDR: FIx a bug

I am writing a linter called sundrylint to address some real-world bugs that I discovered during my work.

When we range over a slice and call the append function within the loop body, we are not appending all elements, but only the ones that we specifically iterate over during the range operation.

for _, n := range ns {
   rs = append(rs, n)       # this is ok
   rs = append(rs, ns...)   # this is wrong
}

I read the code in here https://github.com/vmware-tanzu/velero/blob/main/test/util/velero/velero_utils.go#L171-L174

I think it was just to append the not exists in origin plugins

Does your change fix a particular issue?

Fixes #(issue)

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