Remove unnecessary requirements and allow more Sylius versions

[Prometee]

Related issue #116

• [x] Allow Sylius 1.12 and futur releases
• [x] Add Sylius 1.12 to GitHub Action
• [x] Switch test app to Webpack

[Prometee]

@mamazu my GitHub action are always failing on BeHat tests for apparently no reason or not one I can explain yet, but I tested it locally with Sylius 1.11 and Sylius 1.12.x-dev and there is no error at all.

[Prometee]

@mamazu nail it, my local folder tests/Application/public/build wasn't flush between each of my tests, and that's why I haven't seen the entry point error I had, now the build is running green : https://github.com/Prometee/SyliusCustomOptionsPlugin/actions/runs/3298832922

[mamazu]

Sorry for the late reply, thank you very much for all the work of upgrading the plugin. I will merge and tag it.

[Prometee]

@mamazu no problem it was quick enough 😉 I needed it also to tests my own plugins so : this work on Sylius 1.12, will be reused.