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] <[email protected]>

Author: dependabot[bot]

.github/workflows/alttexter.yml

@@ -27,7 +27,7 @@ jobs:
           echo "REF=${{ github.event.pull_request.head.ref }}" >> $GITHUB_ENV
 
       - name: Checkout
-        uses: actions/checkout@v4.1.1
+        uses: actions/checkout@v6
         with:
           fetch-depth: 1
           ref: ${{ env.REF }}

.github/workflows/build.yml

@@ -28,14 +28,14 @@ jobs:
     steps:
 
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         path: docs
         fetch-depth: 0
         ref: ${{ github.event.pull_request.head.ref || github.ref_name }}
 
     - name: Download Tools
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         repository: ${{ secrets.TOOLS_REPOSITORY }}
         ref: master

.github/workflows/merge-release-notes.yml

@@ -15,13 +15,13 @@ jobs:
     steps:
 
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         path: docs
         token: ${{ secrets.TOOLS_PAT }}
 
     - name: Checkout Tools
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         repository: ${{ secrets.TOOLS_REPOSITORY }}
         ref: master

.github/workflows/smarteditor.yml

@@ -35,7 +35,7 @@ jobs:
           REF=$(curl -s -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" $PR_API_URL | jq -r .head.ref)
           echo "REF=$REF" >> $GITHUB_ENV
       - name: Checkout
-        uses: actions/checkout@v4.1.1
+        uses: actions/checkout@v6
         with:
           fetch-depth: 1
           ref: ${{ env.REF }}

.github/workflows/validate-frontmatter.yml

@@ -9,7 +9,7 @@ jobs:
     name: Validate
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4.1.1
+      - uses: actions/checkout@v6
       - name: Validate Frontmatter
         uses: mheap/frontmatter-json-schema-action@main
         with:

.github/workflows/visual-assets-update-all.yml

@@ -58,7 +58,7 @@ jobs:
     steps:
     - name: Checkout
       if: (github.event_name == 'issue_comment' && needs.ignore-list.outputs.triggered == 'true') || github.event_name != 'issue_comment'
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         fetch-depth: 1
 

.github/workflows/visual-assets-validate.yml

@@ -39,7 +39,7 @@ jobs:
 
     - name: Checkout
       if: inputs.files == '' || steps.count.outputs.number > 0
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         fetch-depth: 1
         ref: ${{ github.event.pull_request.head.ref || github.ref_name }}