BLD: Drop nonexistent dependency of _libs/parsers
Title is self-explanatory.

Follow-up to #22469.
Closes #22831.
Hello @gfyoung! Thanks for submitting the PR.

 - There are no PEP8 issues in the file [`setup.py`](https://github.com/gfyoung/pandas/blob/9414b176934866737a8a374dd0cb50c03bd68de4/setup.py) !

 @jreback @jbrockmendel : Are you able to confirm locally that the rebuild no longer occurs? # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22883?src=pr&el=h1) Report
> Merging [#22883](https://codecov.io/gh/pandas-dev/pandas/pull/22883?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/e45a6c14fc969c31c46ae890e72883ffe6658b4e?src=pr&el=desc) will **not change** coverage.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/22883/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/22883?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master   #22883   +/-   ##
=======================================
  Coverage   92.18%   92.18%           
=======================================
  Files         169      169           
  Lines       50830    50830           
=======================================
  Hits        46860    46860           
  Misses       3970     3970
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.6% <ø> (ø)` | :arrow_up: |
| #single | `42.37% <ø> (ø)` | :arrow_up: |


------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22883?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/22883?src=pr&el=footer). Last update [e45a6c1...9414b17](https://codecov.io/gh/pandas-dev/pandas/pull/22883?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Yep, that solved it for me locally.  Nice catch. @gfyoung thanks!