build(deps): bump actions/checkout from 5 to 6 in the gha-updates group

Bumps the gha-updates group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `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
  dependency-group: gha-updates
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/check-links.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v6

.github/workflows/cpu-tests.yml

@@ -45,7 +45,7 @@ jobs:
     timeout-minutes: 10
     steps:
       - name: Checkout generic
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
@@ -89,10 +89,10 @@ jobs:
     timeout-minutes: 35
     steps:
       - name: Checkout generic
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         if: github.event_name != 'pull_request_target'
       - name: Checkout for `pull_request_target`
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         if: github.event_name == 'pull_request_target'
         with:
           ref: ${{ github.event.pull_request.head.sha }}

.github/workflows/mkdocs-deploy.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       # Step 1: Checkout the repository
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       # Step 2: Set up Python
       - uses: actions/setup-python@v6

.github/workflows/publish-pkg.yml

@@ -20,7 +20,7 @@ jobs:
 
     steps:
       - name: Checkout source
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v6