Bump actions/checkout from 4.1.2 to 4.1.4

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.1.2 to 4.1.4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@9bb5618...0ad4b8f)

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

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

.github/workflows/validate.yml

@@ -20,7 +20,7 @@ jobs:
         sdk: [3.1, stable, beta]
 
     steps:
-      - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       - uses: dart-lang/setup-dart@fedb1266e91cf51be2fdb382869461a434b920a3
         with:
           sdk: ${{ matrix.sdk }}