CLN: Remove some dtype methods from API
Removes the following from the public API:

* `pandas.api.types.is_sequence`
* `pandas.api.types.is_any_int_dtype`
* `pandas.api.types.is_floating_dtype`

xref #16163.
xref #16189.

Hello @gfyoung! Thanks for submitting the PR.

 - There are no PEP8 issues in the file [`pandas/core/dtypes/api.py`](https://github.com/gfyoung/pandas/blob/8110871aaf2b89679e27d6753627fc83b4b943e5/pandas/core/dtypes/api.py) !

 - There are no PEP8 issues in the file [`pandas/core/dtypes/common.py`](https://github.com/gfyoung/pandas/blob/8110871aaf2b89679e27d6753627fc83b4b943e5/pandas/core/dtypes/common.py) !

 - There are no PEP8 issues in the file [`pandas/tests/api/test_types.py`](https://github.com/gfyoung/pandas/blob/8110871aaf2b89679e27d6753627fc83b4b943e5/pandas/tests/api/test_types.py) !

 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23390?src=pr&el=h1) Report
> Merging [#23390](https://codecov.io/gh/pandas-dev/pandas/pull/23390?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/62a15fa4071d0711b2b97771b981d527c1c4af10?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/23390/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/23390?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #23390      +/-   ##
==========================================
- Coverage   92.16%   92.16%   -0.01%     
==========================================
  Files         166      166              
  Lines       51224    51212      -12     
==========================================
- Hits        47212    47198      -14     
- Misses       4012     4014       +2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.59% <ø> (-0.01%)` | :arrow_down: |
| #single | `42.22% <ø> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/23390?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/dtypes/common.py](https://codecov.io/gh/pandas-dev/pandas/pull/23390/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2NvbW1vbi5weQ==) | `94.37% <ø> (-0.49%)` | :arrow_down: |
| [pandas/core/dtypes/api.py](https://codecov.io/gh/pandas-dev/pandas/pull/23390/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2FwaS5weQ==) | `100% <ø> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23390?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/23390?src=pr&el=footer). Last update [62a15fa...49b8c74](https://codecov.io/gh/pandas-dev/pandas/pull/23390?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 can you say these are removed in the whatsnew? 🤦‍♂️ : Totally forgot that.  Thanks!  Will do. @jreback : `whatsnew` added and green. PTAL. thanks!