We are not interested in coverage information when a PR has already been
approved, and we were seeing flakiness with SonarCloud with the "no
artifacts found" error
https://github.com/vector-im/element-web/issues/25334 .
* Switch to composite actions for pr_details and sonarqube
* Bring back a reusable workflow for element-web stack sonarqube runs
* Move sonarcloud.yml to the right repo
* Fix Netlify run
* Split Cypress out into its own workflow
* Improve PR Details job to use github-script and output labels
* Fix wrongly using github.ref in workflow_run actions which always refer to develop
* Update pr-details to be far more generic
* Tweak how we fill command-prefix
