Add automatic deployment to PyPI

Author: oscarbenjamin

.github/workflows/buildwheel.yml

@@ -155,3 +155,33 @@ jobs:
       - run: bin/install_flint_ubuntu.sh ${{ matrix.flint-tag }}
       - run: pip install .
       - run: python -m flint.test --verbose
+
+  # Deploy wheels and sdist to PyPI
+
+  pypi_release:
+    name: Publish to PyPI
+    needs: [build_wheels, build_sdist]
+    # Run only when a tag is pushed to the flintlib/python-flint repo
+    if: "github.event_name == 'push' && startsWith(github.ref, 'refs/tags') && github.owner == flintlib"
+    environment:
+      name: pypi
+      url: https://pypi.org/p/sympy
+    permissions:
+      id-token: write
+    runs-on: ubuntu-latest
+
+    steps:
+        # Downloads all artifacts
+      - name: Download release artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: wheelhouse
+
+      - name: Copy the PyPI files into dist
+        run: mkdir dist && cp wheelhouse/*.whl wheelhouse/*.tar.gz dist
+
+      - name: Publish package on PyPI
+        # It is recommended to pin a commit hash here for security but it
+        # should be kept up to date. Possibly all actions and dependencies used
+        # by the build script should be pinned...
+        uses: pypa/gh-action-pypi-publish@81e9d935c883d0b210363ab89cf05f3894778450  # v1.8.14