CLN: Drop the as_recarray parameter in read_csv
Deprecated back in 0.19.0

xref #13373.

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18804?src=pr&el=h1) Report
> Merging [#18804](https://codecov.io/gh/pandas-dev/pandas/pull/18804?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/c28b6249471ffddfed51d62437a65ca97766fb7f?src=pr&el=desc) will **decrease** coverage by `0.02%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/18804/graphs/tree.svg?token=eZ4WkYLtcO&width=650&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/18804?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #18804      +/-   ##
==========================================
- Coverage   91.64%   91.62%   -0.03%     
==========================================
  Files         154      154              
  Lines       51428    51411      -17     
==========================================
- Hits        47129    47103      -26     
- Misses       4299     4308       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.48% <100%> (-0.01%)` | :arrow_down: |
| #single | `40.84% <100%> (-0.12%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/18804?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/parsers.py](https://codecov.io/gh/pandas-dev/pandas/pull/18804/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3BhcnNlcnMucHk=) | `95.49% <100%> (-0.06%)` | :arrow_down: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/18804/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/18804/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.68% <0%> (-0.11%)` | :arrow_down: |
| [pandas/core/series.py](https://codecov.io/gh/pandas-dev/pandas/pull/18804/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc2VyaWVzLnB5) | `94.82% <0%> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18804?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/18804?src=pr&el=footer). Last update [c28b624...24d4fe5](https://codecov.io/gh/pandas-dev/pandas/pull/18804?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Everything is green now.  If there are no objections, I'll merge later today. pls wait for my review @jreback : Those two functions have been removed, and all is still green.  PTAL. thanks @gfyoung 