Bump actions/checkout from 3.3.0 to 3.5.2 (#402)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.3.0 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@ac59398...8e5e7e5)

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

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

.github/workflows/tests.yml

@@ -15,7 +15,7 @@ jobs:
     container:
       image: crystallang/crystal
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
+      - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab
       - name: Run generator tests
         run: ./bin/test_specs
   template:
@@ -24,7 +24,7 @@ jobs:
     container:
       image: crystallang/crystal
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
+      - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab
       - name: Run file formatting
         run: crystal ./bin/check-format.cr
   exercises:
@@ -37,7 +37,7 @@ jobs:
     container:
       image: crystallang/crystal:${{ matrix.crystal }}
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
+      - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab
       - name: Install jq
         run: apt-get update && apt-get install -y jq
       - name: Run tests