require only one differ, as they have BC breaking changes

[TomasVotruba]

No description provided.

[github-actions]

Hi, thank you for your contribution.

Unfortunately, this repository is read-only. It's a split from our main monorepo repository.

We'd like to kindly ask you to move the contribution there - https://github.com/symplify/symplify.

We'll check it, review it and give you feed back right way.

Thank you.

[TomasVotruba]

@samsonasik I'm currently handling this one, as it's breaking with differ 5 and I need it Rector Symfony rule :) just so you know you can skip adding this one.

[samsonasik]

@TomasVotruba while you're at it, could you enable github action for the following repositories:

• Move symplify/packages/package-builder source here deprecated-packages/package-builder#2
• Move symplify/packages/smart-file-system source here deprecated-packages/smart-file-system#2
• Move symplify/packages/phpstan-extensions source here phpstan-extensions#1

Thank you.

[TomasVotruba]

Yes 👍 done 😉