CI: Build / SonarQube fails on every PR (scanner cannot resolve the pull request) #99

Problem

The Build / SonarQube job fails on every pull request. The failure has nothing to do with the code under review. It fails on the open PRs #97 and #98, and earlier on #89, #90 and #96. These PRs touch unrelated files.

From job 109943428226 (PR #98), the scanner fails while asking the server about the PR:

ERROR Something went wrong while trying to get the pullrequest with key '98'
##[error]Action failed: ... sonar-scanner failed with exit code 3

The scanner cannot resolve the pull-request object on the SonarQube server. The likely causes are a misconfigured project key, a missing ALM binding, or a token without browse permission on the project. The PR's code is not the cause.

Acceptance criteria

• On a fresh PR that touches only a comment, Build / SonarQube concludes success. If the check is intentionally advisory, it concludes neutral/skipped with a logged reason, not failure.
• The root cause, whether the project key, ALM binding or token scope, is named in the fixing PR.
• A pull-request analysis is visible on the SonarQube server for that PR. A green job that never reached the server does not count.

Found while landing #98. #98 inherits this red and does not cause it.