CICD Publish - Bug's and Enhancements

Now that we have an semi [working deployment](https://github.com/ckan/ckanext-xloader/blob/master/.github/workflows/publish.yml#L96).

We need to fix it to be available for other plugins, etc to use.

To fix:
* testpypi publish was skipped when it should have published, [see ](https://github.com/ckan/ckanext-xloader/actions/runs/11358384594/job/31592906156)
* version details from script was not found and not used by later parts of cicd. i.e. "Published @ to " should have been "Published ckanext-xloader @ 1.1.1 to https://pypi.org/project/ckanext-xloader/
* Fix auto publish when tag is pushed.
* Don't continue publish is git tag and python version are not matching

Enhancements:
* Create Service Account bot/worker and have it given access to the repository.
* Setup gpg signing for the Service Account bot and security install into repo github actions secrets (ensure 12+char passphrase is set)
* Setup ssh public/private key for the Service Account bot and install into the repo github actions secrets (ensure 12+char passphrase is set)
* Create Version Bump system based on https://github.com/callowayproject/bump-my-version?tab=readme-ov-file#github-actions using the service account as a signed git committer and push back to repo (so github actions downstream are triggered)