DEPR/CLN: remove SparseTimeSeries class (follow-up GH15098)
#15098 removed the TimeSeries alias, but we also deprecated SparseTimeSeries (#10890), so this makes the removal complete.
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15567?src=pr&el=h1) Report
> Merging [#15567](https://codecov.io/gh/pandas-dev/pandas/pull/15567?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/7ae4fd10b1581d77b4cfbf594e3b444af7456876?src=pr&el=desc) will **decrease** coverage by `-0.04%`.
> The diff coverage is `100%`.


```diff
@@            Coverage Diff             @@
##           master   #15567      +/-   ##
==========================================
- Coverage   91.07%   91.03%   -0.04%     
==========================================
  Files         136      137       +1     
  Lines       49167    49303     +136     
==========================================
+ Hits        44777    44884     +107     
- Misses       4390     4419      +29
```


| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/15567?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/compat/pickle_compat.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL2NvbXBhdC9waWNrbGVfY29tcGF0LnB5) | `68.29% <ø> (ø)` | :white_check_mark: |
| [pandas/sparse/series.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL3NwYXJzZS9zZXJpZXMucHk=) | `95.13% <ø> (-0.06%)` | :x: |
| [pandas/sparse/api.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL3NwYXJzZS9hcGkucHk=) | `100% <100%> (ø)` | :white_check_mark: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :x: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `81.11% <0%> (-0.96%)` | :x: |
| [pandas/tools/merge.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL3Rvb2xzL21lcmdlLnB5) | `91.78% <0%> (-0.35%)` | :x: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.83% <0%> (-0.1%)` | :x: |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `96.25% <0%> (-0.07%)` | :x: |
| [pandas/formats/format.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL2Zvcm1hdHMvZm9ybWF0LnB5) | `95.34% <0%> (-0.07%)` | :x: |
| [pandas/io/json/__init__.py](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?src=pr&el=tree#diff-cGFuZGFzL2lvL2pzb24vX19pbml0X18ucHk=) | `100% <0%> (ø)` | :white_check_mark: |
| ... and [4 more](https://codecov.io/gh/pandas-dev/pandas/pull/15567?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15567?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/15567?src=pr&el=footer). Last update [7ae4fd1...daa7c32](https://codecov.io/gh/pandas-dev/pandas/compare/7ae4fd10b1581d77b4cfbf594e3b444af7456876...daa7c32ac46c63669158580971a17eca602fe40c?el=footer&src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).