build(deps): bump actions/checkout from 6.0.2 to 6.0.3

Bumps [actions/checkout](https://github.com/actions/checkout) from 6.0.2 to 6.0.3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](de0fac2e45...df4cb1c069)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/apidiff.yml

@@ -13,7 +13,7 @@ jobs:
     if: (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name != github.repository)
     steps:
       - name: Clone the code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10
         with:
           fetch-depth: 0
       - name: Setup Go