BUG: don't force clipboard routines to be imported in main pandas
closes #16288 
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=h1) Report
> Merging [#16294](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/4bed864a24901d9c2baab5e17c57c956a188602f?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16294/graphs/tree.svg?src=pr&height=150&width=650&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16294      +/-   ##
==========================================
- Coverage   90.39%   90.37%   -0.02%     
==========================================
  Files         161      161              
  Lines       50863    50863              
==========================================
- Hits        45977    45969       -8     
- Misses       4886     4894       +8
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.16% <100%> (ø)` | :arrow_up: |
| #single | `40.32% <100%> (-0.11%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/clipboards.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2lvL2NsaXBib2FyZHMucHk=) | `100% <ø> (ø)` | |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `91.94% <100%> (ø)` | :arrow_up: |
| [pandas/io/api.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2lvL2FwaS5weQ==) | `100% <100%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.59% <0%> (-0.1%)` | :arrow_down: |
| [pandas/core/common.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY29tbW9uLnB5) | `91.03% <0%> (+0.34%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16294?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/16294?src=pr&el=footer). Last update [4bed864...38a235a](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=h1) Report
> Merging [#16294](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/4bed864a24901d9c2baab5e17c57c956a188602f?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16294/graphs/tree.svg?token=eZ4WkYLtcO&src=pr&height=150&width=650)](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16294      +/-   ##
==========================================
- Coverage   90.39%   90.37%   -0.02%     
==========================================
  Files         161      161              
  Lines       50863    50863              
==========================================
- Hits        45977    45969       -8     
- Misses       4886     4894       +8
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.16% <100%> (ø)` | :arrow_up: |
| #single | `40.32% <100%> (-0.11%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/clipboards.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2lvL2NsaXBib2FyZHMucHk=) | `100% <ø> (ø)` | |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `91.94% <100%> (ø)` | :arrow_up: |
| [pandas/io/api.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2lvL2FwaS5weQ==) | `100% <100%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.59% <0%> (-0.1%)` | :arrow_down: |
| [pandas/core/common.py](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY29tbW9uLnB5) | `91.03% <0%> (+0.34%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16294?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/16294?src=pr&el=footer). Last update [4bed864...38a235a](https://codecov.io/gh/pandas-dev/pandas/pull/16294?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
