✨ add workflow for PyPI releases (based on GitHub releases)

- github release tags a commit, but the action is triggered only by the publishing event of a release

.github/workflows/tox-gha.yml

@@ -1,8 +1,10 @@
 name: Python package
 
 on:
-  - push
-  - pull_request
+  push:
+  pull_request:
+  release:
+    types: [published]
 
 jobs:
   build:
@@ -22,3 +24,27 @@ jobs:
         python -m pip install tox tox-gh-actions
     - name: Test with tox
       run: tox
+
+
+  publish:
+    name: Publish package
+    if: startsWith(github.ref, 'refs/tags')
+    needs:
+      - build
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+      - name: Install twine and build
+        run: python -m pip install --upgrade twine build
+      - name: Build
+        run: python -m build
+
+      - uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          user: __token__
+          password: ${{ secrets.PYPI_API_TOKEN }}