Define Github Action for test-PyPI publication

.github/workflows/publish-to-test-pypi.yml

@@ -0,0 +1,38 @@
+name: Publish Python package to TestPyPI
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  publish:
+    name: Publish to TestPyPI
+    runs-on: ubuntu-latest
+    if: startsWith(github.ref, 'refs/tags/')  # Only run on tagged commits
+
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v4
+      with:
+        python-version: "3.x"
+
+    - name: Install pypa/build/setuptools/twine
+      run: >-
+        python3 -m
+        pip install
+        build setuptools twine
+        --user
+
+    - name: Build a binary wheel and a source tarball
+      run: python3 -m build
+
+    - name: Publish to TestPyPI
+      env:
+        TWINE_USERNAME: __token__
+        TWINE_PASSWORD: ${{ secrets.PYPI_TOKEN }}
+      run: twine upload --repository-url https://test.pypi.org/legacy/ dist/*
+