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/build-docker.yml

@@ -21,7 +21,7 @@ jobs:
             suffix: ""
             continue-on-error: false
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Get version number
         id: get_version

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
                 python-version: ["3.12"]
                 node-version: ["22"]
         steps:
-            - uses: actions/checkout@v5
+            - uses: actions/checkout@v6
             - uses: awalsh128/cache-apt-pkgs-action@v1.6.0
               with:
                   packages: libsasl2-dev python3-dev libxml2-dev libxmlsec1-dev libxslt-dev libxmlsec1-openssl libxslt-dev libldap2-dev libssl-dev gcc musl-dev postgresql-dev zlib-dev jpeg-dev libwebp-dev openssl-dev libffi-dev cargo openldap-dev python3-dev xmlsec-dev xmlsec build-base g++ curl

.github/workflows/codeql-analysis.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     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/docs.yml

@@ -12,7 +12,7 @@ jobs:
     if: github.repository_owner == 'TandoorRecipes' && ${{ github.event.workflow_run.conclusion == 'success' }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: 3.x