Removed emeritus reviewers from SECURITY_CONTACTS

[micahhausler]

What this PR does / why we need it:

Cleanup of emeritus reviewers.

cc @jaypipes @jyotimahapatra @wongma7

[k8s-ci-robot]

@micahhausler: 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
pull-aws-iam-authenticator-unit	d73c1a3	link	true	/test pull-aws-iam-authenticator-unit

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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[nckturner]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: micahhausler, nckturner, orsenthil

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• OWNERS [micahhausler,nckturner]

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