Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/sonarcloud.yml

@@ -11,7 +11,7 @@ jobs:
     name: SonarCloud
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5.0.0
+      - uses: actions/checkout@v6.0.0
         with:
           fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
       - name: SonarCloud Scan