Impossible to use ECS because of PHPStan version

[FabienSalles]

Fix by this merge request : #212

Currently, if you do :

1. git clone https://github.com/Sylius/PluginSkeleton.git
2. composer install
3. vendor/bin/ecs
   You will get an error Class "Symplify\PackageBuilder\Console\HelpfulApplicationTrait" not found while loading "Symplify\EasyCodingStandard\Console\EasyCodingStandardConsoleApplication".
   This php trait is removed in symplify/package-builder

The version of ECS need to be update to 8.3 instead of 8.1 but we can't update it due to phpstan conflict version with the composer.json file.

To reproduce you just have to had "symplify/easy-coding-standard": "8.3.48 as 8.1.19" in require-dev dependencies and see this error :

Problem 1
    - symplify/coding-standard 8.3.48 requires phpstan/phpstan ^0.12.40 -> found phpstan/phpstan[0.12.40, ..., 0.12.64] but it conflicts with your root composer.json require (0.12.25).
    - symplify/easy-coding-standard 8.3.48 requires symplify/coding-standard ^8.3.48 -> satisfiable by symplify/coding-standard[8.3.48].
    - Root composer.json requires symplify/easy-coding-standard 8.3.48 as 8.1.19 -> satisfiable by symplify/easy-coding-standard[8.3.48].

Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.

If you change the version of phpstan with ^0.12 and update, everything will be back to normal.

[FabienSalles]

The PR is merged, I closed