Bump actions/checkout from 5.0.0 to 6.0.0 (#240)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@08c6903...1af3b93)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/rubocop.yml

@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@8aeb6ff8030dd539317f8e1769a044873b56ea71

.github/workflows/tests.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
 
       - name: Setup Ruby
         uses: ruby/setup-ruby@8aeb6ff8030dd539317f8e1769a044873b56ea71
@@ -35,7 +35,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435