Use GHA for reverse dependency check

[IndrajeetPatil]

Doing this is quite resource intensive on local machines and isn't going to scale well, especially as our reverse dependencies continue to grow.

A good place to start would be this repo and adapting it to our needs:
https://github.com/yihui/crandalf

[IndrajeetPatil]

Closed by mistake

[bwiernik]

We can do it conditionally, such as when cutting a release. The psychmeta repo Actions has an example of that

[IndrajeetPatil]

@easystats/maintainers I have created a new workflow for reverse dependency check.

This workflow will be triggered only on PRs coming from branches whose names start with rc (release candidate). Revdepchecks are extremely time-consuming, and so we should run them only when we need to, not on every PR.

So, when you want to create a new release on CRAN and wish to run revdepcheck using GHA, you must create a branch that has this prefix (e.g. rc_cran_0.20.1, rc-insight-0.20, etc.) and then create a PR.