Revert type casting because Symfony forms can return integer keys

[willemverspyck]

Subject

I am targeting this branch, because BC.

Closes #368.

Changelog

### Fixed
- Added the type casting to string, because Symfony forms can return integer keys.

[jordisala1991]

Build is failing, can you fix it?

[willemverspyck]

I don't have many experience with PHP Stan. Do you know how I can solve this @jordisala1991?

[nocive]

@willemverspyck in this case probably the most sane solution will be to instruct phpstan to ignore these 2 errors in particular, but I guess that's up to @jordisala1991 to say :). See here for the various ways phpstan allows you to do that, should that be the course of action taken here.

[willemverspyck]

Thanks @nocive. I though there was a way to define it can also be integer, but just added the ignore comments 👍

[jordisala1991]

Wdyt @VincentLanglet since you previously changed the code

[VincentLanglet]

I think it's all related to phpstan/phpstan-symfony#274
And IMHO there would be more to fix in others repositories.

The issue is the following:

• When using $form->add($foo, ...) you are only allowed to pass a string
• This string is used as an array-key
• When a string representation of an int is passed to an array it's automatically cast to int by php.
  So when you do $form->add('1') then you get the int 1 and you need to cast to string indeed to remove the form back.

I wonder if we should

• revert Fix formInterface stub phpstan/phpstan-symfony#274 to get the phpstan error "You pass string|int when string is expected"
• open an discussion on Symfony about supporting int param
• At least modifying directly on Symfony the phpdoc (https://github.com/symfony/symfony/blob/6.1/src/Symfony/Component/Form/FormInterface.php#L21-L22)
• Changing the behavior of phpstan about array-key

[VincentLanglet]

I opened an issue in Symfony symfony/symfony#46698

[nocive]

Thanks guys! In the meantime is it possible to get this one in and release it?
This is preventing us from updating sonata dependencies without explicit pinning of form-extensions to <1.17

[VincentLanglet]

Will be solved in 6.2 by symfony/symfony#46813