Upgrade `phpdocumentor/reflection-docblock` to v6

[misaert]

Hi,

I see the dependency phpdocumentor/reflection-docblock is not compatible with version 6.

Is this planned?

Thanks,

Mickaël

[ta-tikoma]

@misaert added in 0.8.6

[misaert]

Thank you @ta-tikoma 🙏