chore(deps): update node-exporter-kubernetes (patch)

[renovate]

This PR contains the following updates:

Package	Update	Change
node-exporter-kubernetes	patch	1.9.1-ubuntu24.04u20 → 1.9.1-ubuntu24.04u21
node-exporter-kubernetes	patch	1.9.1-ubuntu22.04u20 → 1.9.1-ubuntu22.04u21
node-exporter-kubernetes	patch	1.9.1-ubuntu20.04u20 → 1.9.1-ubuntu20.04u21

---

Warning

Some dependencies could not be looked up. Check the Dependency Dashboard for more information.

---

Configuration

📅 Schedule: (UTC)

• Branch creation
  • At any time (no schedule defined)
• Automerge
  • At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

👻 Immortal: This PR will be recreated if closed unmerged. Get config help if that's undesired.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[Copilot]

Copilot can't review bot-authored pull requests automatically. A user with Copilot access can request a review manually.

[Copilot]

Copilot can't review bot-authored pull requests automatically. A user with Copilot access can request a review manually.

[Copilot]

Copilot can't review bot-authored pull requests automatically. A user with Copilot access can request a review manually.

[aks-node-assistant]

AgentBaker Linux gate detective RCA for failed run: https://msazure.visualstudio.com/CloudNativeCompute/_build/results?buildId=172270390

• Failed job/task: Run AgentBaker E2E / Run AgentBaker E2E.
• L1 surface failure: gotestsum failed after broad near-immediate E2E skips/failures; first sampled signature is $(System.Collections.Hashtable.sample); 32 missing-image metadata lines were observed.
• L2 corroboration: ADO timeline marks only the E2E job/task failed; test results show E2E failures; the run log reports current-build image lookup missing before VM provisioning.
• L3 root-cause challenge: Product/CSE/VHD regression is less likely because this stops at image discovery before node creation and recurs across unrelated PRs. Best match is known wiki signature �2e-vhd-build-id-unresolved-macro-missing-images (pipeline/config image metadata issue), tracked by repair item #38812052.
• Confidence: medium-high. Strongest alternative: PR-specific change altered expected images, but recurrence across PRs makes gate infrastructure/config more likely.
• Next action: treat as gate flake; follow repair item #38812052 and the wiki row: https://dev.azure.com/msazure/09706533-03bf-4b43-9a9b-b49c75429646/_wiki/wikis/ed4a85e9-1085-4151-a39b-2753523eba2b?pagePath=%2FAKS%2FSIGs%20and%20Teams%2FAKS%20Components%2FSIG%3A%20Node%20Lifecycle%2FAI%20Agent%20Knowledge%2FAgentBaker%20Gate%20PR%20Pipeline%20Flakiness%2FItems%20With%20Repair%20Items