chore: bump actions/checkout from 4.1.5 to 4.1.6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.1.5 to 4.1.6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4.1.5...v4.1.6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/test.yaml

@@ -14,10 +14,10 @@ jobs:
         distro: [humble, iron]
     steps:
       - name: Checkout this repository
-        uses: actions/[email protected].5
+        uses: actions/[email protected].6
 
       - name: Checkout ROS 2 examples
-        uses: actions/[email protected].5
+        uses: actions/[email protected].6
         with:
           repository: ros2/examples
           ref: ${{ matrix.distro }}
@@ -50,10 +50,10 @@ jobs:
         distro: [humble, iron]
     steps:
       - name: Checkout this repository
-        uses: actions/[email protected].5
+        uses: actions/[email protected].6
 
       - name: Checkout ROS 2 examples
-        uses: actions/[email protected].5
+        uses: actions/[email protected].6
         with:
           repository: ros2/examples
           ref: ${{ matrix.distro }}