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] <[email protected]>

Author: dependabot[bot]

.github/workflows/check.yml

@@ -19,7 +19,7 @@ jobs:
           - test:pkglint
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/history-update.yaml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         # Get all of the git history. https://github.com/actions/checkout
         with:
           fetch-depth: 0

.github/workflows/integration.yaml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/python-publish.yaml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0
     - name: Set up Python

.github/workflows/test.yml

@@ -19,7 +19,7 @@ jobs:
           - '3.13'
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0