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] <support@github.com>

Author: dependabot[bot]

.github/workflows/check-general-formatting.yml

@@ -16,7 +16,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install editorconfig-checker
         uses: editorconfig-checker/action-editorconfig-checker@v2

.github/workflows/check-license.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install Ruby
         uses: ruby/setup-ruby@v1

.github/workflows/check-markdown.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Initialize markdownlint-cli problem matcher
         uses: xt0rted/markdownlint-problem-matcher@v3
@@ -50,7 +50,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Determine whether only modified files should be checked
         id: check-modified

.github/workflows/check-prettier-formatting.yml

@@ -212,7 +212,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install Prettier
         run: sudo npm install --global prettier

.github/workflows/check-toc.yml

@@ -29,7 +29,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install markdown-toc
         run: sudo npm install --global markdown-toc

.github/workflows/check-workflows.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Download JSON schema for GitHub Actions workflows
         id: download-schema

.github/workflows/check-yaml.yml

@@ -67,7 +67,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Check YAML
         # yamllint's "colored" output type is useful for humans reading the log.

.github/workflows/spell-check.yml

@@ -16,7 +16,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Spell check
         uses: codespell-project/actions-codespell@master

.github/workflows/sync-labels.yml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Download JSON schema for labels configuration file
         id: download-schema
@@ -106,7 +106,7 @@ jobs:
           echo "::set-output name=flag::--dry-run"
 
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Download configuration file artifacts
         uses: actions/download-artifact@v6