Bump actions/checkout from 3.1.0 to 3.3.0 (#593)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.1.0 to 3.3.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@93ea575...ac59398)

---
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/ci.yml

@@ -14,7 +14,7 @@ jobs:
       RUNALL: "true"
     steps:
       - name: Checkout code
-        uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8
+        uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
 
       - name: Run tests
         run: swift test