Update release workflow

.github/workflows/release.yml

@@ -9,13 +9,13 @@ jobs:
   pypi-publish:
     name: Build and upload release to PyPI
     runs-on: ubuntu-latest
-    if: github.ref == 'refs/heads/main'
     environment: release
     permissions:
       id-token: write
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v4
+      - run: pip install build
       - run: python -m build
       - name: Publish package distributions to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1