chore(deps): update actions/checkout action to v6 (#369)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/hassfest.yaml

@@ -10,5 +10,5 @@ jobs:
   hassfest_custom:
     runs-on: "ubuntu-latest"
     steps:
-      - uses: "actions/checkout@v5.0.1"
+      - uses: "actions/checkout@v6.0.0"
       - uses: home-assistant/actions/hassfest@master

.github/workflows/test.yml

@@ -35,7 +35,7 @@ jobs:
       python-version: ${{ steps.python.outputs.python-version }}
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Set up Python ${{ env.DEFAULT_PYTHON }}
         id: python
         uses: actions/setup-python@v6
@@ -74,7 +74,7 @@ jobs:
       - prepare
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Restore cached environment
         id: cache-reuse
         uses: plugwise/gh-actions/restore-venv@v1
@@ -96,6 +96,6 @@ jobs:
     name: Shellcheck
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5.0.1
+      - uses: actions/checkout@v6.0.0
       - name: Run ShellCheck
         uses: ludeeus/action-shellcheck@master