Bump actions/checkout from 5.0.0 to 6.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Dump environment
         run: env | sort
       - name: Checkout ruby/www.ruby-lang.org
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
         with:
           fetch-depth: 1
       - name: Setup Ruby

.github/workflows/draft-release.yml

@@ -16,9 +16,9 @@ jobs:
     runs-on: ubuntu-latest
     if: github.repository == 'ruby/www.ruby-lang.org'
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6.0.0
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6.0.0
         with:
           repository: ruby/ruby
           path: ruby

.github/workflows/jekyll.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - name: Setup Ruby
         uses: ruby/setup-ruby@a6e6f86333f0a2523ece813039b8b4be04560854 # v1.190.0
         with: