update python-publish.yml

Author: abearab

.github/workflows/python-publish.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v3
       with:
-        python-version: '3.x'
+        python-version: '3.9'
     - name: Install miniconda
       uses: conda-incubator/setup-miniconda@v2
       with:
@@ -39,6 +39,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install setuptools wheel
+        pip install build
     - name: Build package
       run: python -m build
     - name: Publish package