Run specific workflow / workflow for specific repositories

[Geod24]

Hello,
The D Programming Language has some extended testing for its core components (e.g. the compiler), which includes running the test-suite of popular projects on each PR to ensure that no regression is introduced.

This is currently done via Buildkite (for configuration) + agents being spawned on demand. We used to rely on the Travis-ci configuration whenever we could so we could reduce duplication between the project's own CI scripts and our CI code.

However, with Travis' open source offer going the way of the Dodo, and the rise of Github workflows, this isn't so useful anymore. Hence we'd like to have support to natively run Github actions. I'm aware of act but it looks like using this repository might be a more foolproof approach.

So, my questions are:

• Is there currently something / some way to do this simply that I'm not aware of ?
• If not, what would be the best way to go about it ?
  I was considering trying to emulate a pull_request event to the tested repo.
  I don't think I need to provide context / secrets for this, which reduces the scope of the work.