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

Author: renovate[bot]

.github/workflows/main.yml

@@ -6,7 +6,7 @@ jobs:
     container: node:lts
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v6
       - name: Prepare
         run: npm ci
       - name: Publish