chore(deps): update actions/checkout action to v6

Author: renovate-bot

.github/workflows/claude-code-review.yml

@@ -48,7 +48,7 @@ jobs:
             return pr;
 
       - name: Checkout PR branch
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           ref: ${{ github.event_name == 'workflow_dispatch' && steps.pr-info.outputs.ref || github.event.pull_request.head.ref }}
           repository: ${{ github.event_name == 'workflow_dispatch' && steps.pr-info.outputs.repo || github.event.pull_request.head.repo.full_name }}

.github/workflows/claude.yml

@@ -26,7 +26,7 @@ jobs:
       actions: read # Required for Claude to read CI results on PRs
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 1