TST/CLN: Parameterize test in sparse/test_indexing
Title is self-explanatory.
Hello @gfyoung! Thanks for submitting the PR.

 - There are no PEP8 issues in the file [`pandas/tests/sparse/test_indexing.py`](https://github.com/gfyoung/pandas/blob/4ceebc3c22ebd1752fbb3e9e034fe433a82146cb/pandas/tests/sparse/test_indexing.py) !

 I expect to have Azure fail until #23182 is merged. # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23213?src=pr&el=h1) Report
> Merging [#23213](https://codecov.io/gh/pandas-dev/pandas/pull/23213?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/1546c35dc839b3f6c094ad41d14cda24e9e13a0c?src=pr&el=desc) will **not change** coverage.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/23213/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/23213?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master   #23213   +/-   ##
=======================================
  Coverage   92.19%   92.19%           
=======================================
  Files         169      169           
  Lines       50954    50954           
=======================================
  Hits        46975    46975           
  Misses       3979     3979
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.61% <ø> (ø)` | :arrow_up: |
| #single | `42.27% <ø> (ø)` | :arrow_up: |


------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23213?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/23213?src=pr&el=footer). Last update [1546c35...5b68ad4](https://codecov.io/gh/pandas-dev/pandas/pull/23213?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 > A few small comments (also want to try out this new "suggestion" feature).

In the context of `pandas`, the fact that each applied suggestion is a new commit means we're going to trigger CI for each applied suggestion, which is not ideal unfortunately.  Interesting feature though... > My only gripe with the feature is that it is going to fire new commits every time.

Yeah, and doesn't look like there's a way to do multi-line edits.  Probably good if there's a single one line change that needs to be made, but otherwise might not be worthwhile atm.

>Each commit (at least for this repository) is going to trigger CI IIUC.

Is CI smart enough to cancel the job if a newer commit has been made?  I've seen it do so in some similar scenarios before, but not sure what the exact logic around that is. CI do cancel older builds if newer ones appear
though only if they didn’t start > CI do cancel older builds if newer ones appear
though only if they didn’t start

Ideally, though Circle was having issues with that... @jreback : Addressed all comments, and all is green again!  PTAL. Thanks!