Supporting symfony 6
Supporting symfony 6

I'm trying to test symfony 6, But I'm getting this error

```
stof/doctrine-extensions-bundle dev-master requires symfony/config ^4.4 || ^5.2 -> found symfony/config[v4.4.0-BETA1, ..., 4.4.x-dev, v5.2.0-BETA1, ..., 5.4.x-dev] but these were not loaded, likely because it conflicts with another require.
```
stof/StofDoctrineExtensionsBundle