PR validation now runs on your own fork of com-lihaoyi/mill before running on the primary repo

[lihaoyi]

Since #3543

Please open all PRs as drafts and ensure that your fork of Mill has
settings/actions / Allow all actions and reusable workflows enabled to run CI on
your own fork of the Mill repo. Only once CI passes mark the PR as Ready for review
and CI will run on the main Mill repo before we merge it.

This should spread out the CI load across everyone's individual accounts (each of which
as a separate Github Actions quota) and help avoid bottlenecks where everyone is waiting
for GHA workers to be available to test their PR.

[gamlerhart]

I get this hint about running CI in drafts. I assume by clicking to the right we mean the 'Details'?

And there check the status of the last commit:

I assume that is meant by 'click to right'?

[lihaoyi]

@gamlerhart yes that's right.

The new Github PR UI just moved the link to the left, will update the message once that's all rolled out