Wrap publishing steps into composite actions.

We follow a pattern in our package repos where we create a `CI_CD.yml` workflow that calls some reusable workflows from `shared`, but our publishing jobs in each `CI_CD.yml` are multistep jobs calling 3rd-party actions. These publishing jobs don't work properly when called from a reusable workflow, which prevents us from wrapping all the jobs in each consuming repo's `CI_CD.yml` into a single reusable workflow in `shared`. So, if we update how we do CI/CD, it often means we need to update all the `CI_CD.yml` files in each repo.

We may be able to use GitHub's composite actions to wrap up the publishing steps and the whole CI/CD pipeline into one reusable workflow. https://docs.github.com/en/actions/sharing-automations/avoiding-duplication

See https://github.com/crickets-and-comb/shared/issues/53

Start by reviewing the package repositories' CI_CD.yml workflows, the reusable workflows in shared, and shared issue 53, then read GitHub's guidance on composite actions. Done means the publishing steps can be wrapped for use by the reusable CI/CD workflow without requiring equivalent publishing-job changes in every consuming repository.

Written by the indexing model from the issue text.