add an action to publish to testpypi

Signed-off-by: Ruth Fuchss <[email protected]>

.github/workflows/publish-to-testpypi.yml

@@ -0,0 +1,47 @@
+name: Publish canonical-sphinx-extensions to TestPyPI
+on: workflow_dispatch
+jobs:
+  build:
+    name: Build package
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Install pypa/build
+      run: >-
+        python -m
+        pip install
+        build
+        --user
+    - name: Build a binary wheel and a source tarball
+      run: >-
+        python -m
+        build
+        --sdist
+        --wheel
+        --outdir dist/
+        .
+    - name: Store the package
+      uses: actions/upload-artifact@v3
+      with:
+        name: python-package
+        path: dist/
+  publish:
+    name: Publish to TestPyPI
+    needs:
+    - build
+    runs-on: ubuntu-latest
+    environment:
+      name: testpypi
+      url: https://test.pypi.org/p/canonical-sphinx-extensions
+    permissions:
+      id-token: write
+    steps:
+    - name: Download package
+      uses: actions/download-artifact@v3
+      with:
+        name: python-package
+        path: dist/
+    - name: Publish to PyPI
+      uses: pypa/gh-action-pypi-publish@release/v1
+      with:
+        repository-url: https://test.pypi.org/legacy/