Bump actions/checkout from 4 to 5 (#585)

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

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -37,7 +37,7 @@ jobs:
             python-version: "3.13"
             os: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0 # Fetch all history for all branches and tags.
       - name: Set environment variables
@@ -88,7 +88,7 @@ jobs:
       matrix:
         python-version: ["3.11", "3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0 # Fetch all history for all branches and tags.
       - name: Set up conda environment

.github/workflows/pypi.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.repository == 'xarray-contrib/cf-xarray'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       - uses: actions/setup-python@v5

.github/workflows/testpypi-release.yaml

@@ -17,7 +17,7 @@ jobs:
     if: ${{ contains( github.event.pull_request.labels.*.name, 'test-build') && github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch' }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
 

.github/workflows/upstream-dev-ci.yaml

@@ -31,7 +31,7 @@ jobs:
       matrix:
         python-version: ["3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0 # Fetch all history for all branches and tags.
       - name: Set environment variables