Keep narwhals when testing polars!

Author: mwouts

.github/workflows/continuous-integration.yml

@@ -58,12 +58,11 @@ jobs:
             numpy-version: '<2.0'
           - python-version: "3.13"
             pandas-version: pre
-          - python-version: "3.13"
-            polars: true
           - python-version: "3.12"
-            modin: false
           - python-version: "3.12"
             modin: true
+          - python-version: "3.13"
+            polars: true
           - python-version: "3.13"
             uninstall_narwhals: true
           - python-version: "3.13"