dratify: the release workflow now tests the tag it publishes

dratify’s release pipeline could report a successful release that published nothing: ci.yml triggers on branches and pull requests and never on tags, so no test ever ran against the ref being published, and combined with skip-existing a tag that forgot to bump the version built the old one, had PyPI skip it as already present, and exited green. The suite now runs on the tag, and the build fails when the tag does not name the version it produced — skip-existing should absorb a re-run of the same release, not disguise a forgotten bump.