Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/publish.yml

@@ -8,7 +8,7 @@ jobs:
   publish-npm:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - uses: actions/setup-node@v4
         with:
           node-version: 18

.github/workflows/test.yml

@@ -5,7 +5,7 @@ jobs:
   build:
     runs-on: macos-latest
     steps:
-    - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
+    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
     - name: Use Node.js
       uses: actions/setup-node@v4
       with: