CI test tweak.

.github/workflows/ci.yml

@@ -53,7 +53,6 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           python -m pip install build
-          python -m pip install pytest
 
       - name: Build sdist and wheel
         run: |
@@ -130,6 +129,7 @@ jobs:
           # make sure we test the installed code
           cp -R repo/tests/ tests/
           python -m pip install --upgrade pip
+          python -m pip install pytest
           python -m pip install ./dist/*.whl
           # show the directory contents for diagnostics
           ls -la