Update PHP CS Fixer config file name

[MaxGiting]

I was trying to fix the failing StyleCI flag.

It seems that everything after June 14th, 2020 started failing which from this blog looks to be around the time that StyleCI changed its default behaviour to disable "risky" fixers. Which also matches the warning on all failure messages from StyleCI.

https://blog.styleci.io/platform-improvements/

I cannot see why the .yml file settings of risky: true has not fixed or even changed the error message. StyleCI does mention you can override the .yml file settings in your StyleCI dashboard. I don't know if you have done that.