Run spin build first

Author: oscarbenjamin

.github/workflows/buildwheel.yml

@@ -134,6 +134,7 @@ jobs:
 
       - run: pip install --upgrade pip
       - run: pip install -r requirements-dev.txt
+      - run: spin build
       - run: spin run -- pytest --doctest-glob='*.rst' doc/source
       - run: spin docs