Bump actions/checkout from 5 to 6 (backport #363) (#366)

Author: mergify[bot]

.github/workflows/ci-format.yml

@@ -15,7 +15,7 @@ jobs:
     name: Format
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: '3.10'

.github/workflows/ci-ros-lint.yml

@@ -11,7 +11,7 @@ jobs:
       matrix:
         linter: [copyright, lint_cmake]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ros-tooling/setup-ros@v0.7
       - uses: ros-tooling/action-ros-lint@v0.1
         with:

.github/workflows/reusable_ici.yml

@@ -41,7 +41,7 @@ jobs:
         uses: actions/checkout@v5
       - name: Checkout ${{ inputs.ref_for_scheduled_build }} on scheduled build
         if: ${{ github.event_name == 'schedule' }}
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ inputs.ref_for_scheduled_build }}
       - run: docker network create --subnet=192.168.56.0/24 ursim_net