Add package upload step to release-pipeline using Twine

Author: lithorus

.github/workflows/release-pipeline.yml

@@ -41,6 +41,11 @@ jobs:
           echo "opencue_cueadmin_path=$(ls -a packages/opencue_cueadmin-*.whl)" >> $GITHUB_OUTPUT
           echo "opencue_cuegui_path=$(ls -a packages/opencue_cuegui-*.whl)" >> $GITHUB_OUTPUT
 
+      - name: Upload packages
+        run: |
+          python3 -m pip install --upgrade twine
+          python3 -m twine upload --repository testpypi packages/*
+
   build_docker_images:
     needs: build_python_packages
     runs-on: ubuntu-22.04