Bump actions/checkout from 3.5.0 to 3.5.2 (dart-lang#116)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.5.0 to 3.5.2.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@8f4b7f8...8e5e7e5)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/validate.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3
+      - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab
 
       - name: Check for sources
         run: |