NO-JIRA: Update openstack approvers

[mandre]

Emilien is changing teams. Proposing Stephen as the co-maintainer for OpenStack.

[mandre]

/cc @EmilienM

[openshift-ci-robot]

@mandre: This pull request explicitly references no jira issue.

In response to this:

Emilien is changing teams. Proposing Stephen as the co-maintainer for OpenStack.

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[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mandre

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Needs approval from an approver in each of these files:

• OWNERS [mandre]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[pierreprinetti]

LGTM

[EmilienM]

/lgtm

[pierreprinetti]

/retest-required

[openshift-ci]

@mandre: 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/hypershift-aws-e2e-external	c5471a0	link	true	/test hypershift-aws-e2e-external

Full PR test history. Your PR dashboard.

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