Update upload_to_pypi.yml

Author: lukeshingles

.github/workflows/upload_to_pypi.yml

@@ -20,6 +20,8 @@ jobs:
 
       - uses: actions/setup-python@v5
         name: Install Python
+        with:
+          python-version: '3.x'
 
       - name: Build wheels
         # For very recent Python versions, wheels from e.g. numpy might not be
@@ -41,6 +43,8 @@ jobs:
 
       - uses: actions/setup-python@v5
         name: Install Python
+        with:
+          python-version: '3.x'
 
       - name: Install build
         run: python -m pip install build