Drop deprecated phpstan configuration options

[greg0ire]

Q	A
Type	improvement
BC Break	no
Fixed issues	n/a

Summary

PHPStan warns about them, says they are probably no longer required.

⚠️  You're using a deprecated config option autoload_files. ⚠️️

You might not need it anymore - try removing it from your
configuration file and run PHPStan again.

If the analysis fails, there are now two distinct options
to choose from to replace autoload_files:
1) scanFiles - PHPStan will scan those for classes and functions
   definitions. PHPStan will not execute those files.
2) bootstrapFiles - PHPStan will execute these files to prepare
   the PHP runtime environment for the analysis.

Read more about this in PHPStan's documentation:
https://phpstan.org/user-guide/discovering-symbols

⚠️  You're using a deprecated config option autoload_directories. ⚠️️

You might not need it anymore - try removing it from your
configuration file and run PHPStan again.

If the analysis fails, replace it with scanDirectories.