chore(deps): bump actions/upload-artifact from 4 to 6 (#1129)

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -42,7 +42,7 @@ jobs:
 
 
       - name: Archive code coverage results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: ${{ env.CODE_COVERAGE_ARTIFACT_NAME }}
           path: "stackit/${{ env.CODE_COVERAGE_FILE_NAME }}"