fix(ci): bump sonarqube-scan-action v4 → v6 to fix command/argument injection vulns

Resolves GHSA-f79p-9c5r-xg88 and GHSA-5xq9-5g24-4g6f.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: saby1101

.github/workflows/build.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
-      - uses: SonarSource/sonarqube-scan-action@v4
+      - uses: SonarSource/sonarqube-scan-action@v6
         env:
           SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
           SONAR_HOST_URL: ${{ secrets.SONAR_HOST_URL }}