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

Author: renovate[bot]

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
       issues: write
       pull-requests: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v4
         with:
           node-version: 20.x

.github/workflows/update-snapshots.yml

@@ -13,7 +13,7 @@ jobs:
       contents: write
       pull-requests: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: checkout pr
         run: gh pr checkout "$PR_NUMBER"
         env: