Bump to Submariner 0.21

[skitt]

This includes a bump to Go 1.24 and Kubernetes 1.33.

[openshift-ci]

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[sonarqubecloud]

Quality Gate passed

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0 New issues
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[openshift-ci]

@skitt: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/verify	058c1da	link	true	/test verify

Full PR test history. Your PR dashboard.

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