Draft usage of PyPI action.

.github/workflows/package.yml

@@ -12,7 +12,26 @@ jobs:
     steps:
       - name: Checkout branch
         uses: actions/checkout@v4
+      - name: Set up pixi
+        uses: prefix-dev/[email protected]
+      - name: Build
+        run: |
+          pixi run python -m build
+      - uses: actions/upload-artifact@v4
         with:
-          ref: ${{ github.head_ref }}
-          fetch-depth: 0
-      # TODO: Build and upload to PyPI.
+          path: dist/*
+
+  upload_pypi:
+    name: Upload to PyPI
+    needs: [build_artifacts]
+    runs-on: ubuntu-latest
+    if: github.event_name == 'release' && github.event.action == 'published'
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: artifact
+          path: dist
+      - uses: pypa/[email protected]
+        with:
+          user: __token__
+          password: ${{ secrets.PYPI_TOKEN }}