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] <support@github.com>

Author: dependabot[bot]

.github/workflows/pr-checks.yml

@@ -10,7 +10,7 @@ jobs:
     name: Check Actions
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Changelog check
         uses: Zomzog/changelog-checker@09cfe9ad3618dcbfdba261adce0c41904cabb8c4 # v1.3.0
         with:

.github/workflows/release.yml

@@ -10,7 +10,7 @@ jobs:
     name: publish release
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Verify tag is on main branch

.github/workflows/test-ros1.yml

@@ -31,7 +31,7 @@ jobs:
             os: ubuntu-latest
             python-version: "3.11"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with:

.github/workflows/test-ros2.yml

@@ -35,7 +35,7 @@ jobs:
             os: ubuntu-latest
             python-version: "3.12"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with: