Bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/black.yml

@@ -6,7 +6,7 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: psf/black@stable
         with:
           src: "./post_processing/rayleigh.py"

.github/workflows/docker.yml

@@ -21,7 +21,7 @@ jobs:
     if: github.repository == 'geodynamics/rayleigh'
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3

.github/workflows/main.yml

@@ -34,7 +34,7 @@ jobs:
     container: geodynamics/rayleigh-buildenv-jammy
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - name: Build documentation
       # First make sure notebooks do not contain output, then build doc
       run: |
@@ -116,7 +116,7 @@ jobs:
         shell: bash -l {0}
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - uses: conda-incubator/setup-miniconda@v3
       with:
         activate-environment: radev