Replace tar_csv.tar.gz with gzipped tar
tar was not compressed previously

cc @gfyoung  ```
(pandas) bash-3.2$ ls pandas/tests/io/parser/data/
iris.csv                salaries.csv.bz2        salaries.csv.zip        tar_csv.tar             test1.csv.bz2           test_mmap.csv           tips.csv.gz             utf16_ex_small.zip
items.jsonl             salaries.csv.gz         sauron.SHIFT_JIS.csv    tar_csv.tar.gz          test1.csv.gz            tips.csv                unicode_series.csv
salaries.csv            salaries.csv.xz         sub_char.csv            test1.csv               test2.csv               tips.csv.bz2            utf16_ex.txt
```

? @jreback try `ls -l`, you'll see `tar_csv.tar` and `tar_csv.tar.gz` are both 10240 bytes in size. # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22269?src=pr&el=h1) Report
> Merging [#22269](https://codecov.io/gh/pandas-dev/pandas/pull/22269?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/2c2b6585c1c45889d32491b4a0403617a2d48e17?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/22269/graphs/tree.svg?width=650&height=150&src=pr&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/22269?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master   #22269   +/-   ##
=======================================
  Coverage   92.08%   92.08%           
=======================================
  Files         169      169           
  Lines       50694    50694           
=======================================
  Hits        46682    46682           
  Misses       4012     4012
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.49% <ø> (ø)` | :arrow_up: |
| #single | `42.34% <ø> (ø)` | :arrow_up: |


------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22269?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/22269?src=pr&el=footer). Last update [2c2b658...9bc8d7d](https://codecov.io/gh/pandas-dev/pandas/pull/22269?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Thanks @ginggs !