build(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...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] <support@github.com>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -30,7 +30,7 @@ jobs:
       LD: ${{ matrix.cc }}
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Ruby version
         run: ruby -v
       - name: Compiler version
@@ -45,7 +45,7 @@ jobs:
       MRUBY_CONFIG: ci/msvc
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Ruby version
         run: ruby -v
       - name: Build and test

.github/workflows/coverage.yml

@@ -16,7 +16,7 @@ jobs:
       LDFLAGS: --coverage
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Ruby version
         run: ruby -v
       - name: Compiler version

.github/workflows/lint.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Install
         run: |
           python -m pip install --upgrade pip

.github/workflows/release.yml

@@ -19,7 +19,7 @@ jobs:
       fail-fast: false
     steps:
       - name: "Checkout ${{ github.ref_name }} ( ${{ github.sha }} )"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Builds
         id: builds
         run: |

.github/workflows/super-linter.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           # Full git history is needed to get a proper list of changed files within `super-linter`
           fetch-depth: 0