Bump actions/checkout from 5 to 6 in the dependencies group (#99)

Bumps the dependencies group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 5 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

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

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/swift.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - name: Install libssl-dev
         run: apt-get update && apt-get install -y libssl-dev
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Build
         run: swift build -c release -Xswiftc -strict-concurrency=complete
       - name: Run tests
@@ -27,6 +27,6 @@ jobs:
     name: SwiftLint version 3.2.1
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: GitHub Action for SwiftLint
         uses: norio-nomura/action-swiftlint@3.2.1