Use actions/checkout@v6

Use this link to re-run the recipe: https://app.moderne.io/recipes/org.openrewrite.github.ChangeActionVersion?organizationId=QUxML01vZGVybmUvTW9kZXJuZSArIE9wZW5SZXdyaXRl#defaults=W3sidmFsdWUiOiJhY3Rpb25zL2NoZWNrb3V0IiwibmFtZSI6ImFjdGlvbiJ9LHsidmFsdWUiOiJ2NiIsIm5hbWUiOiJ2ZXJzaW9uIn1d

Co-authored-by: Moderne <team@moderne.io>

Author: timtebeek

.github/workflows/sdkman-candidates.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0