Merge pull request #114 from xenit-eu/renovate/actions-checkout-6.x

Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     name: "build"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - uses: actions/setup-java@v5