build: bump actions/checkout from 5 to 6 (#366)

Bumps [actions/checkout](https://github.com/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
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
@@ -26,7 +26,7 @@ jobs:
         run: sudo apt-get update && sudo apt-get install --no-install-recommends -y build-essential git libyaml-dev pkg-config
 
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1

.github/workflows/codeql.yml

@@ -29,7 +29,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -27,7 +27,7 @@ jobs:
       id-token: write
     environment: release
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Set up Ruby