This functionality has been missed because I seem to have an allergic reaction to YAML.

User MarcinOrlowski kindly recommended a more intuitive syntax to use for the path argument:

- name: PHPStan
  uses: php-actions/phpstan@v3
  with:
    path: example/dir1 example/dir2 example/dir3 ...etc.

is counter intuitive, as in yaml you should do normal list instead

path: 
    - example/dir1example/dir2
    - example/dir2
    - example/dir3
    - ...etc