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] <[email protected]>

Author: dependabot[bot]

.github/workflows/pypi.yml

@@ -11,7 +11,7 @@ jobs:
     if: ${{ github.repository == 'p4lang/p4runtime-shell' }}
     runs-on: [ubuntu-latest]
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up Python
       uses: actions/setup-python@v5
       with:

.github/workflows/test.yml

@@ -19,7 +19,7 @@ jobs:
           - 5000:5000
     steps:
     - name: Check-out code
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v3
       with:

.github/workflows/toc.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Check-out code
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Update TOCs
       run: make toc
     - name: Check for changes