After digging into your repo, I think I have a better understanding of what’s happening.
You were likely impacted by this change:
Since your PRs come from forked repos, they don’t have access to the SONAR_TOKEN repository secret. My guess is you may have been relying on the Anyone permission as a workaround, and this workaround stopped working two weeks ago.
SonarQube Cloud doesn’t support analysis on forked PRs particularly well, which is a shame as it makes it hard to support open-source development workflows. In those situations, we generally recommend Automatic Analysis, though you should be aware that some features like code coverage might not be available.
Some users have come up with creative solutions to address this (without exposing a SonarQube Cloud token). Here’s a recent example: