chore(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] <[email protected]>

Author: dependabot[bot]

.github/workflows/codeql-analysis.yml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         # We must fetch at least the immediate parents so that if this is
         # a pull request then we can checkout the head.

.github/workflows/tests.yml

@@ -44,11 +44,11 @@ jobs:
           wget -nc https://ftp.debian.org/debian/pool/main/o/openssl/libssl1.1_1.1.1w-0+deb11u1_amd64.deb
           sudo dpkg -i libssl1.1_1.1.1w-0+deb11u1_amd64.deb
       # end libssl1.1 install
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         if: github.event.inputs.git-ref == ''
         with:
           fetch-depth: 0 # always fetch everything to be sure for codecov
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         if: github.event.inputs.git-ref != ''
         with:
           ref: ${{ github.event.inputs.git-ref }}
@@ -92,7 +92,7 @@ jobs:
     needs: [tests]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Use Node.js 20
         uses: actions/setup-node@v6
         with:

.github/workflows/website-pr.yml

@@ -12,7 +12,7 @@ jobs:
       contents: read # for actions/checkout to fetch code
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Use Node.js 24
         uses: actions/setup-node@v6
         with:

.github/workflows/website.yml

@@ -22,7 +22,7 @@ jobs:
       contents: write  # for JamesIves/github-pages-deploy-action to push changes in repo
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Use Node.js 24
         uses: actions/setup-node@v6
         with: