Bump actions/checkout from 5 to 6 (#124)

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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -11,7 +11,7 @@ jobs:
     steps:
       # For tags we assume the version in setup.py is correct!
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: 'recursive'
       - name: Rewrite version for dev if not tag

.github/workflows/linting.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     name: Linting
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: 'recursive'
       - name: Set up Python 3.11
@@ -33,7 +33,7 @@ jobs:
     runs-on: ubuntu-latest
     name: Code Format
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: 'recursive'
       - name: Set up Python 3.11
@@ -55,7 +55,7 @@ jobs:
       matrix:
         python-version: [ "3.11", "3.12", "3.13" ]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: 'recursive'
       - name: Set up Python ${{ matrix.python-version }}

.github/workflows/test.yml

@@ -20,7 +20,7 @@ jobs:
         python-version: [ "3.11", "3.12", "3.13" ]
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: 'recursive'
       - name: Set up Python ${{ matrix.python-version }}