Bump actions/checkout from 5 to 6 (#46)

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
         julia-version: ["1", "lts"]
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.julia-version }}

.github/workflows/documenter.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     if: "contains( github.event.pull_request.labels.*.name, 'preview docs') || github.ref == 'refs/heads/main' || contains(github.ref, 'refs/tags/')"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: julia-actions/setup-julia@latest
         with:
           version: "1.12"

.github/workflows/format.yml

@@ -18,7 +18,7 @@ jobs:
       issues: write
       pull-requests: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       # - uses: julia-actions/setup-julia@v2
       #   with:
       #     version: '1'

.github/workflows/nightly.yml

@@ -11,7 +11,7 @@ jobs:
         julia-version: ["pre"]
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.julia-version }}