Update virtual-nodes-cli.md

[jacobbaek]

beta.kubernetes.io/os label deprecated.
https://kubernetes.io/docs/reference/labels-annotations-taints/#beta-kubernetes-io-os-deprecated

[prmerger-automator]

@jacobbaek : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change.

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[v-regandowner]

@Nickomang - Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team

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[v-dirichards]

@Nickomang - Could you review this proposed update to your article and enter #sign-off in a comment if it's ready to merge?

Thanks!