upgrade: update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/publish.yml

@@ -12,7 +12,7 @@ jobs:
       id-token: write
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dart-lang/setup-dart@v1
       - uses: flutter-actions/[email protected]
       - name: Install dependencies