Bump actions/checkout from 4 to 5 (#54)

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

Author: dependabot[bot]

.github/workflows/test-external.yaml

@@ -24,7 +24,7 @@ jobs:
           - "3.4"
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{matrix.ruby}}

.github/workflows/test.yaml

@@ -48,7 +48,7 @@ jobs:
             ruby: "2.5"
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{matrix.ruby}}