Improve versioning for package

Current process:
* code is checked out
* dev dependencies are installed
* use hatch to calculate current version and next version
* update version using hatch in __about__.py
* build the package
* upload package
* commit changes made in __about__.py to the repo.

Future process:
* use [github releases](https://docs.github.com/en/repositories/releasing-projects-on-github/managing-releases-in-a-repository) for versions
* eliminate use of __about__.py to cache the version

[spar example](https://github.com/bcgov/nr-spar-backend/blob/main/.github/workflows/merge-main.yml)

Review the current packaging workflow, the version cache in __about__.py, and the linked GitHub Releases guidance; compare the intended approach with the spar example workflow. Done means releases provide the package version, the __about__.py update and commit are no longer needed, and the package still builds and uploads successfully.

Written by the indexing model from the issue text.