Cucumber update PRs don't trigger CI

[ciaranmcnulty]

See comment on #222

[stof]

For this to work, the workflow should probably use a dedicated bot account (using an organization-specific github app and authenticating as that app in the workflow) to get a token instead of using the default GHA token (which does not chain triggers when it opens a PR)

[acoulton]

@stof yes, that's my plan when I can get back to this.

One challenge is I don't have access to create / manage a github app for the Behat org, or to configure secrets for github actions. Do you?

The other is that we may need a separate repo to send the PRs from (e.g. Behat/Gherkin-automation-prs) because currently the branch protection rules cover everything so we can't create or delete arbitrary branches in this repo.

[stof]

We would need to work with @ciaranmcnulty or @everzet so that they grant admin access on the organization to active maintainers instead of only write access.