BUG: testing on windows
- we are passing builds which actually have an error
- fix the small dtype issue
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15445?src=pr&el=h1) Report
> Merging [#15445](https://codecov.io/gh/pandas-dev/pandas/pull/15445?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/29aeffb8d77f56c3a3862a6bfaee993aa7660500?src=pr&el=desc) will **decrease** coverage by `-0.01%`.
> The diff coverage is `n/a`.


```diff
@@            Coverage Diff             @@
##           master   #15445      +/-   ##
==========================================
- Coverage   90.37%   90.37%   -0.01%     
==========================================
  Files         135      135              
  Lines       49464    49463       -1     
==========================================
- Hits        44704    44703       -1     
  Misses       4760     4760
```


| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/15445?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/window.py](https://codecov.io/gh/pandas-dev/pandas/compare/29aeffb8d77f56c3a3862a6bfaee993aa7660500...187af834abb4e298893ac2cf536775ea8d1c4164?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvd2luZG93LnB5) | `96.18% <ø> (-0.01%)` | :x: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15445?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15445?src=pr&el=footer). Last update [29aeffb...a5b7fb3](https://codecov.io/gh/pandas-dev/pandas/compare/29aeffb8d77f56c3a3862a6bfaee993aa7660500...a5b7fb3e94142b890eafc417405c27c18bebf25a?el=footer&src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).