Bump actions/checkout from 4 to 5 (#246)

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
     outputs:
       triggered: ${{ steps.detect-trigger.outputs.trigger-found }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 2
       - uses: xarray-contrib/ci-trigger@v1
@@ -40,7 +40,7 @@ jobs:
 
     steps:
       - name: checkout the repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           # need to fetch all tags to get a correct version
           fetch-depth: 0 # fetch all branches and tags
@@ -72,7 +72,7 @@ jobs:
 
     steps:
       - name: checkout the repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: setup python
         uses: actions/setup-python@v5

.github/workflows/nightly.yml

@@ -23,7 +23,7 @@ jobs:
     outputs:
       triggered: ${{ steps.detect-trigger.outputs.trigger-found }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 2
       - uses: xarray-contrib/ci-trigger@v1
@@ -58,7 +58,7 @@ jobs:
 
     steps:
       - name: checkout the repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           # need to fetch all tags to get a correct version
           fetch-depth: 0 # fetch all branches and tags

.github/workflows/publish.yml

@@ -11,7 +11,7 @@ jobs:
     if: github.repository == 'keewis/blackdoc'
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Set up Python
         uses: actions/setup-python@v5
         with: