CI: Add GHA workflow recipe for staging pkgs to PyPI, release-pypi.yml

.github/workflows/release-pypi.yml

@@ -0,0 +1,35 @@
+# Stage Python source distribution and wheel packages through GitHub Actions (GHA) to Python Package Index (PyPI).
+name: Release to PyPI
+
+on:
+  push:
+    tags:
+      - '*.*.*'
+
+jobs:
+  build-and-publish:
+    name: Build & publish package to PyPI
+    runs-on: ubuntu-latest
+    if: startsWith(github.event.ref, 'refs/tags')
+    steps:
+      - name: Acquire sources
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+          cache: 'pip'
+          cache-dependency-path: 'pyproject.toml'
+
+      - name: Build package
+        run: |
+          python -m pip install build twine
+          python -m build
+          twine check dist/{*.tar.gz,*.whl}
+
+      - name: Publish package to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          user: __token__
+          password: ${{ secrets.PYPI_API_TOKEN }}