[release-0.29] Update golang to 1.21

[jkh52]

This completes #569

[k8s-ci-robot]

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[jkh52]

/assign @liangyuanpeng

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[jkh52]

/assign @cheftako

[liangyuanpeng]

LGTM,Thanks.

[cheftako]

/lgtm