Bump actions/checkout from 5 to 6 (#2895)

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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/benchmarks.yml

@@ -34,7 +34,7 @@ jobs:
         run: uv pip install --system numpy pandas tqdm tabulate matplotlib solara networkx scipy
       # Benchmarks on the projectmesa main branch
       - name: Checkout main branch
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: main
           repository: projectmesa/mesa
@@ -50,7 +50,7 @@ jobs:
           name: timings-main
           path: benchmarks/timings_1.pickle
       - name: Checkout PR branch
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         if: github.event_name == 'pull_request_target'
         with:
           ref: ${{ github.event.pull_request.head.ref }}

.github/workflows/build_lint.yml

@@ -40,7 +40,7 @@ jobs:
           #  python-version: 'pypy-3.8'
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with:
@@ -65,7 +65,7 @@ jobs:
   examples:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
@@ -77,7 +77,7 @@ jobs:
       - name: Install Mesa
         run: uv pip install --system .[examples]
       - name: Checkout mesa-examples
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: projectmesa/mesa-examples
           path: mesa-examples

.github/workflows/release.yml

@@ -28,7 +28,7 @@ jobs:
       id-token: write
     steps:
       - name: Checkout source
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Set up Python
         uses: actions/setup-python@v6
         with: