CLN: Remove deprecated method
These params are no longer in the method, therefore can remove the docs strings

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22324?src=pr&el=h1) Report
> Merging [#22324](https://codecov.io/gh/pandas-dev/pandas/pull/22324?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/601d71fcfa9081fa88e5c20148972cd766396cd7?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/22324/graphs/tree.svg?height=150&width=650&token=eZ4WkYLtcO&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/22324?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #22324      +/-   ##
==========================================
- Coverage   92.08%   92.08%   -0.01%     
==========================================
  Files         169      169              
  Lines       50706    50699       -7     
==========================================
- Hits        46691    46684       -7     
  Misses       4015     4015
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.48% <ø> (-0.01%)` | :arrow_down: |
| #single | `42.33% <ø> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/22324?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/22324/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9kYXRldGltZXMucHk=) | `95.5% <ø> (-0.05%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22324?src=pr&el=continue).
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> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22324?src=pr&el=footer). Last update [601d71f...376e48c](https://codecov.io/gh/pandas-dev/pandas/pull/22324?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 we are not removing 0.21.0 deprecations yet, see the list here: https://github.com/pandas-dev/pandas/issues/6581

things deprecated in 0.20.0 are fair game however. Okay no worries, thanks @jreback for the info! @jreback : That was my mistake.  I was under the impression that `0.21.0` was fair game.

@alimcmaster1 : Sorry about that!  I think given we'll remove this method soon, let's leave the docs as is.  We can always make this removal later.