Add renovatebot to update regularly the repository

[thrix]

Looking at MRs like #3197, we could make this automatic, for example once a release maybe.

Is anybody against adding RenovateBot here?

They offer a github app:

https://github.com/apps/renovate/

And pre-commit module is available:

https://docs.renovatebot.com/modules/manager/pre-commit/

@teemtee/admin let me know what you think.