Bump actions/checkout from 5 to 6

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]>

Author: dependabot[bot]

.github/workflows/bundle-update.yml

@@ -11,7 +11,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1

.github/workflows/c-check.yml

@@ -9,7 +9,7 @@ jobs:
   format-check:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: "3.4"

.github/workflows/comments.yml

@@ -13,7 +13,7 @@ jobs:
     # env:
     #   RUBY_COMMIT: 1b0c46daed9186b82ab4fef1a4ab225afe582ee6
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: "3.4.5"

.github/workflows/dependabot.yml

@@ -17,7 +17,7 @@ jobs:
         uses: dependabot/fetch-metadata@08eff52bf64351f401fb50d4972fa95b9f2c2d1b # v2.4.0
         id: metadata
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Abort if blocker files are changed

.github/workflows/ruby.yml

@@ -35,7 +35,7 @@ jobs:
     env:
       RANDOMIZE_STDLIB_TEST_ORDER: "true"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
@@ -76,7 +76,7 @@ jobs:
       matrix:
         ruby: ['3.4', head]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install dependencies
         run: |
           brew install ruby-build

.github/workflows/typecheck.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: "3.3"

.github/workflows/valgrind.yml

@@ -19,7 +19,7 @@ jobs:
   valgrind:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: "3.4"

.github/workflows/windows.yml

@@ -15,7 +15,7 @@ jobs:
       matrix:
         ruby: ['3.2', '3.3', ucrt, mswin]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: load ruby
         uses: ruby/setup-ruby@v1
         with: