Update Owners file

[johnugeorge]

As part of our regular community contributions review, I propose to

1. Add @tenzen-y to the approver list.

@tenzen-y has been very active in Katib in code reviews and tracking issues in Katib. He has contributed more than 50 PRs in last 1 year and has contributed in various design proposals. Ref: https://github.com/kubeflow/katib/commits?author=tenzen-y

Thank you @tenzen-y for all contributions and making Katib better.

2. Remove users who were not active in Katib for last two years .

@hougangliu @sperlingxx Please let us know if you still want to contribute to Katib. Happy to add you back.

/assign @kubeflow/wg-automl-leads

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: johnugeorge

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [johnugeorge]

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

[gaocegege]

/lgtm

@tenzen-y Thanks for your contribution!

[tenzen-y]

@kubeflow/wg-automl-leads Thanks for giving me the honors opportunity!

[andreyvelich]

Thank you so much for all of your hard work and long-term commitment for the Kubeflow community @tenzen-y.
Looking forward to our next steps!
/lgtm