Bump actions/checkout from 1 to 4 (#33)

Bumps [actions/checkout](https://github.com/actions/checkout) from 1 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v1...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  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>

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
         arch:
           - x64
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.version }}

.github/workflows/docs.yml

@@ -18,7 +18,7 @@ jobs:
     name: Build documentation (${{ github.event_name }})
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
         with:
           # Build documentation on Julia 1.5

.github/workflows/doctests.yml

@@ -17,7 +17,7 @@ jobs:
       - uses: julia-actions/setup-julia@latest
         with:
           version: ${{ matrix.julia-version }}
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v4
       - name: Install dependencies
         run: julia --project=docs/ -e 'using Pkg; Pkg.develop(PackageSpec(path=pwd())); Pkg.instantiate()'
       - name: Fix doctests

.github/workflows/format_check.yml

@@ -17,7 +17,7 @@ jobs:
       - uses: julia-actions/setup-julia@latest
         with:
           version: ${{ matrix.julia-version }}
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v4
       - name: Instantiate `format` environment and format
         run: |
           julia  --project=format -e 'using Pkg; Pkg.instantiate()'

.github/workflows/push_preview_cleanup.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout gh-pages branch
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           ref: gh-pages