Add SonarQube scan step to PR validation workflow

Author: Locatelli-Flor

.github/workflows/pr-validation.yml

@@ -67,6 +67,13 @@ jobs:
         severity: 'CRITICAL,HIGH'
         exit-code: '0'
 
+    - name: SonarQube Scan
+      uses: sonarsource/sonarqube-scan-action@v2
+      with:
+        host: https://sonarqube.reto-ucu.net/
+        login: ${{ secrets.SONAR_TOKEN }}
+        projectKey: reto-xmas-2025-goland-ia-backend
+
   pr-summary:
     name: PR Summary
     runs-on: ubuntu-latest