Remove mrbobbytables as enhancements subproject owner

[mrbobbytables]

I haven't been able to give enhancements the attention it deserves =/ With that, opting to step down. Happy to join a meeting or talk about tooling and workflow stuff - just shouldn't be a blocker for anything in repo^^;;

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mrbobbytables

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[sftim]

SLATFATF

[jeefy]

/lgtm