Add tests for the republisher

[schomatis]

To avoid issues like ipfs/kubo#5925 (comment).

[aschmahmann]

This repository is no longer maintained and has been copied over to Boxo. In an effort to avoid noise and crippling in the Boxo repo from the weight of issues of the past, we are closing most issues and PRs in this repo. Please feel free to open a new issue in Boxo (and reference this issue) if resolving this issue is still critical for unblocking or improving your usecase.

You can learn more in the FAQs for the Boxo repo copying/consolidation effort.