Bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
       matrix:
         ruby: ["2.5", "2.6", "2.7", "3.0", "3.1", "3.2", "3.3", "3.4", "head"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -36,7 +36,7 @@ jobs:
   rubocop:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -51,7 +51,7 @@ jobs:
       matrix:
         ruby: ["2.5", "ruby"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with: