[Durable-ownership] Maintainer is not in the exec-sponsor chain

[Rannir]

Hello, As part of our further enhancement for durable ownership, on December 10th we will begin to require all maintainers to be in the exec_sponsors organization.

We have found that this service will fail this requirement, and would like to ask it to be resolved beforehand. Please make sure to fix it here: https://github.com/github/ownership/blob/main/github/github/open-source/ownership.yaml#L418 @barradam @aprilla