The release job for gpu-post is not working as expected

[fasmat]

The release job defined in build.yml doesn't work as expected. It only runs when the push that triggered the execution of the Github action happened on master and included a new git tag.

Instead the release job should be triggered on: release (see https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#release), re-use the existing jobs to build the library for all supported platforms (see also https://docs.github.com/en/actions/using-workflows/reusing-workflows#calling-a-reusable-workflow) and then append the release with the artifacts produced by the build jobs.