build(deps): 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/links.yml

@@ -13,7 +13,7 @@ jobs:
     name: Linkspector
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run linkspector
         uses: umbrelladocs/action-linkspector@v1
         with:

.github/workflows/lints.yml

@@ -12,7 +12,7 @@ jobs:
         name: Markdown
         runs-on: ubuntu-latest
         steps:
-        - uses: actions/checkout@v5
+        - uses: actions/checkout@v6
         - uses: DavidAnson/markdownlint-cli2-action@v20
           with:
             fix: true
@@ -23,7 +23,7 @@ jobs:
         name: Spelling
         runs-on: ubuntu-latest
         steps:
-        - uses: actions/checkout@v5
+        - uses: actions/checkout@v6
         - uses: streetsidesoftware/cspell-action@v8
           with:
             files: "**/*.md"

.github/workflows/matlab-repo-patch.yml

@@ -10,7 +10,7 @@ jobs:
     matlab-repo-patch:
         runs-on: ubuntu-latest
         steps:
-        - uses: actions/checkout@v5
+        - uses: actions/checkout@v6
           with:
             token: ${{ secrets.MATLAB_REPO_INIT_PATCH }}
         - uses: djmaxus/matlab-repo-init/.github/actions/patch@v0.18.0

.github/workflows/matlab.yml

@@ -9,7 +9,7 @@ jobs:
         release: [R2023a, R2024b]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: matlab-actions/setup-matlab@v2
         with:
           release: ${{ matrix.release }}

.github/workflows/release-please.yml

@@ -26,7 +26,7 @@ jobs:
           release-type: simple
           target-branch: main
       - if: ${{ steps.release.outputs.release_created }}
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
       - name: Tag annotation

.github/workflows/webpage-build.yml

@@ -8,7 +8,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: actions/configure-pages@v5
     - uses: actions/jekyll-build-pages@v1
       with: