BUG: Fix #13213 json_normalize() and non-ascii characters in keys
- [ ] closes #13213 
- [ ] tests added / passed
- [ ] passes `git diff upstream/master | flake8 --diff`
- [ ] whatsnew entry

pls add a whatsnew note
 move the test to where I indicated
 ## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/13214?src=pr) is **84.15%**

> Merging [#13214](https://codecov.io/gh/pydata/pandas/pull/13214?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will increase coverage by **<.01%**

``` diff
@@             master     #13214   diff @@
==========================================
  Files           138        138          
  Lines         50388      50394     +6   
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
+ Hits          42386      42408    +22   
+ Misses         8002       7986    -16   
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last updated by [2429ec5...44745ca](https://codecov.io/gh/pydata/pandas/compare/2429ec5a3be278a2fb444eb2aae0c9b05b05cb62...44745ca323ee73924c6413eb4bec3dbe660a2155)
 thanks @fmarczin !
 Thank you for taking care of this so fast!
