Bump actions/checkout from 4 to 5 (#274)

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/DocsPreviewCleanup.yml

@@ -16,7 +16,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout gh-pages branch
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           ref: gh-pages
       - name: Delete preview and history + push changes

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
         arch:
           - x64
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.version }}
@@ -53,7 +53,7 @@ jobs:
       pull-requests: read  # Required when using `push_preview=true`
       statuses: write  # Optional, used to report documentation build statuses
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: julia-actions/setup-julia@v2
         with:
           version: '1'