Automated cherry pick of #93600: Fix panic on /readyz

[ialidzhikov]

Cherry pick of #93600 on release-1.18.

#93600: Fix panic on /readyz

For details on the cherry pick process, see the cherry pick requests page.

Fixes a regression in kube-apiserver causing 500 errors from the `/readyz` endpoint

[k8s-ci-robot]

Hi @ialidzhikov. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[ialidzhikov]

/kind regression
/priority critical-urgent

[wojtek-t]

/ok-to-test
/lgtm
/approve

@liggitt @logicalhan

@kubernetes/release-managers - for cherrypick approval

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ialidzhikov, wojtek-t

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• staging/src/k8s.io/apiserver/OWNERS [wojtek-t]

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[ialidzhikov]

/retest