test unix-like syntax

Author: twoertwein

.github/workflows/test.yml

@@ -54,5 +54,4 @@ jobs:
 
     - if: matrix.python-version == '3.10' && matrix.os == 'ubuntu-latest'
       name: Run pytest (against pandas nightly)
-      continue-on-error: true
-      run: poetry run poe pytest --nightly
+      run: poetry run poe pytest --nightly ; exit 1 || true