Bump actions/checkout from 3 to 4 (#70)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...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/lint-markdown.yaml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up Ruby
         # See https://github.com/ruby/setup-ruby#versioning

.github/workflows/lint-yaml.yaml

@@ -30,7 +30,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Check YAML files with linter
         uses: ibiqlik/action-yamllint@v3
         with:

.github/workflows/test_macos_1.yml

@@ -28,7 +28,7 @@ jobs:
     timeout-minutes: 15
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install coreutils
         run: |
           set -eo pipefail

.github/workflows/test_macos_2.yml

@@ -25,7 +25,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Run Setup new Mac machine script
         run: |

.github/workflows/test_macos_3.yml

@@ -20,7 +20,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Run _macos script
         run: |
           set -eo pipefail

.github/workflows/test_macos_4.yml

@@ -26,7 +26,7 @@ jobs:
     timeout-minutes: 15
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install new vim
         run: |
           set -eo pipefail

.github/workflows/test_ubuntu.yml

@@ -28,7 +28,7 @@ jobs:
     timeout-minutes: 15
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Run setup_dotfiles.sh
         run: |
           set -e