It's important to provide an actual release process for Beman libraries. Providing source releases with version numbers and tarballs (and zip files) is very helpful for package management workflows. It's sometimes possible to package against a specific commit, but it's generally important for versions to be a partially sorted sequence of releases.

Releasing and versioning is also important if and when there are security vulnerabilities detected against a release of this project. CVEs are issued against a set of affected versions of a project. User of Beman libraries would presumably want automatable ways to detect that their released software that includes a Beman library was possibly exposed to a published vulnerability.
  
As to implementation, it makes sense to eventually have some sort of on-merge action that supports releasing automatically. I suspect there are off-the-shelf GitHub actions for that. Though it might be faster, temporarily, to add maintainer documentation about when and how to perform a release. Possibly that documentation could be placed in or near the Beman Standard so that release practices are consistent across the Beman organization.