Backport of [Kubernetes Secret Engine]: Role namespace configuration possible via LabelSelector into release/1.9.x

[hc-github-team-secure-vault-core]

Backport

This PR is auto-generated from #16240 to be assessed for backporting due to the inclusion of the label backport/1.9.x.

WARNING automatic cherry-pick of commits failed. Commits will require human attention.

merge conflict error: POST https://api.github.com/repos/hashicorp/vault/merges: 409 Merge conflict []

The below text is copied from the body of the original PR.

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See https://github.com/hashicorp/vault-plugin-secrets-kubernetes/pull/10

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Overview of commits

• a850381b7fcc32d65207e23c6dcfea613e89bf14

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[tvoran]

Closing since k8s secrets engine debuted in Vault 1.11.x