Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/sync.yml

@@ -21,7 +21,7 @@ jobs:
  environment: sync
  steps:
  - name: clone git-sdk-64
- uses: actions/checkout@v3
+ uses: actions/checkout@v4
  with:
  persist-credentials: true
  token: ${{ secrets.PUSH_TOKEN }}