CLN: Drop the .reshape method from classes
Remove the method for Series, Categorical, and Index. Deprecated or errored in v0.19.0

xref #13012
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18954?src=pr&el=h1) Report
> Merging [#18954](https://codecov.io/gh/pandas-dev/pandas/pull/18954?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/674cf4ff66266f7cc6aff0261e7fcdfcfcfbcf84?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/18954/graphs/tree.svg?src=pr&width=650&token=eZ4WkYLtcO&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/18954?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #18954      +/-   ##
==========================================
- Coverage   91.59%   91.59%   -0.01%     
==========================================
  Files         150      150              
  Lines       48964    48949      -15     
==========================================
- Hits        44850    44835      -15     
  Misses       4114     4114
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.95% <ø> (-0.01%)` | :arrow_down: |
| #single | `41.14% <ø> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/18954?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/18954/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY2F0ZWdvcmljYWwucHk=) | `95.91% <ø> (-0.03%)` | :arrow_down: |
| [pandas/core/indexes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/18954/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9iYXNlLnB5) | `96.44% <ø> (-0.01%)` | :arrow_down: |
| [pandas/core/series.py](https://codecov.io/gh/pandas-dev/pandas/pull/18954/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc2VyaWVzLnB5) | `94.61% <ø> (-0.05%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18954?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/18954?src=pr&el=footer). Last update [674cf4f...c8b5d92](https://codecov.io/gh/pandas-dev/pandas/pull/18954?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 thanks!