Bump actions/checkout from 3 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v3...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/dependabot.yaml

@@ -0,0 +1,11 @@
+---
+version: 2
+updates:
+  - package-ecosystem: 'bundler'
+    directory: '/'
+    schedule:
+        interval: 'weekly'
+  - package-ecosystem: 'github-actions'
+    directory: '/'
+    schedule:
+        interval: 'weekly'

.github/workflows/test.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
     
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1