⚠️ Default selectors to Nothing if it is nil for MatchingLabelsSelector and MatchingFieldsSelector

[acumino]

If the selector is not set for MatchingLabelsSelector and MatchingFieldsSelector, then the list call panics.
This PR updates MatchingLabelsSelector and MatchingFieldsSelector to default their Selector fields to labels.Nothing() and fields.Nothing() respectively if unset in ApplyToList.

[k8s-ci-robot]

Hi @acumino. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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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[acumino]

/cc @sbueringer

[troy0820]

/ok-to-test

[k8s-ci-robot]

LGTM label has been added.

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Git tree hash: 16a47334870891aed9482e6966ba44660880fdb8

[alvaroaleman]

/hold

in case @sbueringer wants to check

[sbueringer]

Thx!

/lgtm
/approve
/hold cancel

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: acumino, alvaroaleman, sbueringer

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