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)
- [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] <[email protected]>

.github/workflows/sync.yml

@@ -21,7 +21,7 @@ jobs:
     environment: ${{ inputs.environment }}
     steps:
       - name: Checkout OEA Repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: OIDC Login to Azure Public Cloud with AzPowershell (enableAzPSSession true)
         uses: azure/login@v1
         with: