Bump actions/checkout from 3 to 4

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]>

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install Ruby and gems
         uses: ruby/setup-ruby@52b8784594ec115fd17094752708121dc5dabb47 # v1.92
@@ -57,7 +57,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Install Ruby and gems
         uses: ruby/setup-ruby@52b8784594ec115fd17094752708121dc5dabb47 # v1.92
         with:
@@ -74,7 +74,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Restore cache
         uses: actions/cache@v3
@@ -106,7 +106,7 @@ jobs:
       SECRET_KEY_BASE: precompile_placeholder
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install Ruby and gems
         uses: ruby/setup-ruby@52b8784594ec115fd17094752708121dc5dabb47 # v1.92