Bump actions/checkout from 3.3.0 to 3.4.0 (#211)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.3.0 to 3.4.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@ac59398...24cb908)

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

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

.github/workflows/build.yaml

@@ -24,7 +24,7 @@ jobs:
     name: build on ${{ matrix.os }} for ${{ matrix.sdk }}
 
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
+      - uses: actions/checkout@24cb9080177205b6e8c946b17badbe402adc938f
       - uses: dart-lang/setup-dart@a57a6c04cf7d4840e88432aad6281d1e125f0d46
         with:
           sdk: ${{ matrix.sdk }}