Update project-maintainers.csv

[oguchinaoki]

Add a maintainer to CoHDI sandbox project

Checklist for maintainer updates

Note

Delete this template if you're not changing the CSV file

• You've provided a link to documentation where the project has approved the maintainer changes.
• The maintainer(s) also created or updated their LFX Individual Dashboard profile.
• You've sent an email with the list of email address(es) to cncf-maintainer-changes@cncf.io for invitations to Service Desk and mailing lists. You can just mark this complete if you are only removing people.
• Optional: You've also sent a PR with affiliation updates to cncf/gitdm.

[github-actions]

✅ PR Requirements Complete

All required checkboxes have been completed. This PR is ready to be handled and merged.

[github-actions]

📋 Maintainer Changes Summary

The following maintainer changes are ready to handle:

Project	Maintainer Name	Company	Email	GitHub Handle	Change
CoHDI	Kensuke Koda	NTT	Shared by email	dakensuk	✅ Add