fix(ci): bump sonarcloud.yml to org reusable workflow SHA 6bad2f898 and correct sonar-organization

[williaby]

Problem

• `sonarcloud.yml` delegates to the org `python-sonarcloud.yml` reusable workflow but is pinned to stale SHA `4e32cdb5e1096fa94cfa3efbcd908d75dd9ef68b`; should be `6bad2f898be1d387b8424e9deddefa519674cb19` (which resolves the `/analysis/analyses` 404 bug on new projects by upgrading to `sonarqube-scan-action` v7.2.0 per org PR 43)
• `sonar-organization` in `sonarcloud.yml` is `ByronWilliamsCPA` but should be `williaby` (the actual SonarCloud account name)

Fix

Apply the same changes made in ByronWilliamsCPA/llc-manager#10:

1. Update the SHA in `sonarcloud.yml` from `4e32cdb5e1096fa94cfa3efbcd908d75dd9ef68b` to `6bad2f898be1d387b8424e9deddefa519674cb19`
2. Correct `sonar-organization` to `williaby` in `sonarcloud.yml`

Reference

• org `.github` PR 43: removed concurrency blocks from reusable callees; upgraded sonarqube-scan-action to v7.2.0
• org `.github` PR 44: documented pull-requests:write relay requirement
• llc-manager PR 10: reference implementation