BUG: Groupby cumprod nan influences other columns with skipna False
- [ ] closes #xxxx (Replace xxxx with the Github issue number)
- [x] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

Saw this when working on mask support

previously this returned

```
      b    c
0  22.0  1.0
1   NaN  NaN
2   NaN  3.0
```

because the calculation in the second row was skipped for the second column after the NaN was encountered
Thanks @phofl 