Update pypi.yml

Author: ColmTalbot

.github/workflows/pypi.yml

@@ -21,7 +21,7 @@ jobs:
         python-version: 3.9
     - name: Install pypa/build
       run: >-
-        python -m pip install build --user
+        python -m pip install build setuptools_scm --user
     - name: Build a binary wheel and a source tarball
       run: >-
         python -m build --sdist --wheel --outdir dist/ .