DOC: hide warning from arrow about deprecated MultiIndex labels
This is fixed upstream in arrow (https://github.com/apache/arrow/pull/3120), but until a new release is there, avoiding the warning in our docs to have a cleaner doc build output.
sure # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=h1) Report
> Merging [#24591](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/db051b94d50cec2a5f2a160b36d67716c47839c7?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24591/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24591      +/-   ##
==========================================
+ Coverage   92.36%   92.36%   +<.01%     
==========================================
  Files         166      166              
  Lines       52497    52497              
==========================================
+ Hits        48489    48490       +1     
+ Misses       4008     4007       -1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.79% <ø> (ø)` | :arrow_up: |
| #single | `43.03% <ø> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/24591/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `88.09% <0%> (+0.09%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24591?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/24591?src=pr&el=footer). Last update [db051b9...5f707b0](https://codecov.io/gh/pandas-dev/pandas/pull/24591?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/24591?src=pr&el=h1) Report
> Merging [#24591](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/db051b94d50cec2a5f2a160b36d67716c47839c7?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24591/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24591      +/-   ##
==========================================
+ Coverage   92.36%   92.36%   +<.01%     
==========================================
  Files         166      166              
  Lines       52497    52497              
==========================================
+ Hits        48489    48490       +1     
+ Misses       4008     4007       -1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.79% <ø> (ø)` | :arrow_up: |
| #single | `43.03% <ø> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/24591/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `88.09% <0%> (+0.09%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24591?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/24591?src=pr&el=footer). Last update [db051b9...5f707b0](https://codecov.io/gh/pandas-dev/pandas/pull/24591?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
