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](https://github.com/actions/checkout/compare/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>

.github/workflows/codespell.yml

@@ -9,7 +9,7 @@ jobs:
     name: Check for spelling errors
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: codespell-project/actions-codespell@master
         with:
           skip: ca_hashes.txt,tls_data.txt,*.pem,OPENSSL-LICENSE.txt,CREDITS.md,openssl.cnf,fedora-dirk-ipv6.diff,testssl.1

.github/workflows/docker-3.3dev.yml

@@ -22,7 +22,7 @@ jobs:
         run: echo "REPO=${GITHUB_REPOSITORY@L}" >> "${GITHUB_ENV}"
 
       - name: Source checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup QEMU
         id: qemu

.github/workflows/shellcheck.yml

@@ -29,7 +29,7 @@ jobs:
     env:
       LANG: C.UTF-8
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Install shellcheck
         run: sudo apt update && sudo apt install -y shellcheck && shellcheck --version

.github/workflows/unit_tests_macos.yml

@@ -29,7 +29,7 @@ jobs:
     name: PoC unit test on MacOS
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up system (perl, curl is installed already)
         run: |

.github/workflows/unit_tests_ubuntu.yml

@@ -32,7 +32,7 @@ jobs:
         perl: ['5.38']
     name: Unit test on ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Set up perl
         uses: shogo82148/actions-setup-perl@v1