fix env var name

Author: gjtorikian

.github/workflows/tag_and_release.yml

@@ -63,7 +63,7 @@ jobs:
           mkdir -p $HOME/.gem
           touch $HOME/.gem/credentials
           chmod 0600 $HOME/.gem/credentials
-          printf -- "---\n:rubygems_api_key: ${GEM_HOST_API_KEY}\n" > $HOME/.gem/credentials
+          printf -- "---\n:rubygems_api_key: ${RUBYGEMS_API_BOT_KEY}\n" > $HOME/.gem/credentials
           bundle exec rake package
           for gem in pkg/html-pipeline-${{ steps.version-label.outputs.version }}*.gem ; do
             gem push "$gem" --host https://rubygems.org