Use latest stable pandas builds on CI

Author: honno

.github/workflows/test.yml

@@ -17,7 +17,7 @@ jobs:
       run: |
         pip install ray git+https://github.com/modin-project/modin
         pip install vaex  # use stable as no nightly builds and long build time
-        pip install git+https://github.com/pandas-dev/pandas --no-deps --ignore-installed  # TODO: use nightly builds again
+        pip install pandas --no-deps --ignore-installed  # use stable as erroneous nightly builds and long build time
     - name: Run tests
       run: |
         pytest tests/ -v --ci