BUG: make Series.sort_values(ascending=[False]) behave as ascending=False (#15604)
 - [X ] closes #15604 
 - [ X] tests added / passed
 - [X] passes ``git diff upstream/master | flake8 --diff``
 - [X] whatsnew entry
bit more testing / validation & please add a whatsnew note. ping when green. All fixed hopefully. There is already a whatsnew line added. Is it the wrong file? no whatsnew is good (I may have been looking at something else). lgtm. ping on green. Sorry, it is my first patch ever here. What is green? How do I ping? The contributors document does not say. @MLopez-Ibanez another comment above.

See those 'pending checks', when the CI runs those will eventually turn green (or red if there is an error).

pinging is when everything is green, just say hey all green. (or really when you need a review if someone doesn't do it first). # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15607?src=pr&el=h1) Report
> Merging [#15607](https://codecov.io/gh/pandas-dev/pandas/pull/15607?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/c52ff68a536fafc0204c5afea57abb943a6c37ce?src=pr&el=desc) will **decrease** coverage by `-0.04%`.
> The diff coverage is `100%`.


```diff
@@            Coverage Diff             @@
##           master   #15607      +/-   ##
==========================================
- Coverage   91.03%      91%   -0.04%     
==========================================
  Files         137      143       +6     
  Lines       49309    49301       -8     
==========================================
- Hits        44887    44864      -23     
- Misses       4422     4437      +15
```


| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/15607?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/series.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc2VyaWVzLnB5) | `94.91% <100%> (+0.01%)` | :white_check_mark: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :x: |
| [pandas/util/depr_module.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvZGVwcl9tb2R1bGUucHk=) | `78.94% <0%> (-9.95%)` | :x: |
| [pandas/tools/merge.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL3Rvb2xzL21lcmdlLnB5) | `91.76% <0%> (-0.36%)` | :x: |
| [pandas/tseries/common.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvY29tbW9uLnB5) | `89.15% <0%> (-0.13%)` | :x: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.87% <0%> (-0.1%)` | :x: |
| [pandas/tseries/tdi.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvdGRpLnB5) | `90.23% <0%> (-0.08%)` | :x: |
| [pandas/core/missing.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvbWlzc2luZy5weQ==) | `84.9% <0%> (-0.05%)` | :x: |
| [pandas/tseries/tools.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvdG9vbHMucHk=) | `84.89% <0%> (-0.05%)` | :x: |
| [pandas/core/ops.py](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvb3BzLnB5) | `91.66% <0%> (-0.05%)` | :x: |
| ... and [38 more](https://codecov.io/gh/pandas-dev/pandas/pull/15607?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15607?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/15607?src=pr&el=footer). Last update [c52ff68...6678574](https://codecov.io/gh/pandas-dev/pandas/compare/c52ff68a536fafc0204c5afea57abb943a6c37ce...667857423e11da4a60d1ded426f70a849a13973d?el=footer&src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments). @jreback Hey all green! thanks @MLopez-Ibanez 

keep em coming!