BUG: Fix failing MacPython 32bit wheels for groupby rolling
- [x] closes #34410
- [ ] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`

What would be the best way to validate that this fixes the MacPython/pandas-wheels @TomAugspurger 
If you really wanted to, you could build a docker image with these changes.

```Dockerfile
FROM quay.io/pypa/manylinux1_i686:latest  # verify this is the right image.

RUN git clone --depth=1 https://github.com/mroeschke/pandas/mac32_rolling \
 && cd pandas \
 && /opt/python/cp37-cp37/bin/python -m pip install numpy cython python-dateutil pytz
WORKDIR pandas

RUN /opt/python/cp38-cp38/bin/python setup.py build_ext -i
```

We really need to get this hooked up to our CI here, but it isn't 100% straightforward. Wondering if something like this would work?

https://docs.microsoft.com/en-us/azure/devops/pipelines/process/container-phases?view=azure-devops > Wondering if something like this would work?

Yeah that's 100% what we need. Just integrating it into the current layout isn't straightforward.

There's also the fact that Anaconda stopped building 32-bit linux package, making this somewhat hard to test. Here's a working Dockerfile if it helps. This is just Py37, could extend to others simply using something like this:

https://github.com/pypa/python-manylinux-demo/blob/84dc72039a0c85c1c960e024f024fd3d37387634/travis/build-wheels.sh#L18

```sh
FROM quay.io/pypa/manylinux1_i686:latest

RUN git clone -b mac32_rolling https://github.com/mroeschke/pandas.git \
 && cd pandas \
 && /opt/python/cp37-cp37m/bin/python -m pip install numpy cython python-dateutil pytz
WORKDIR pandas

RUN /opt/python/cp37-cp37m/bin/python setup.py build_ext -i -j4
```

FWIW still fails to build but I think errors are just what @TomAugspurger is fixing in #34416 

For this change in particular (being python-level only) we probably need an extra step to actually execute the tests if we wanted to verify quickly that way we should drop 32 bit support (for 1.1) I think this and the other 32 bit fixup are fine to merge if it gets the wheel building moving along @TomAugspurger 