Merge pull request #8 from PowerGridModel/dependabot/github_actions/actions/checkout-6

Bump actions/checkout from 5 to 6

Author: mgovers

.github/workflows/sync-headers.yml

@@ -27,7 +27,7 @@ jobs:
       contents: write
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Setup python
         uses: actions/setup-python@v6