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] <support@github.com>

.github/workflows/gempush.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Ruby 2.6
         uses: actions/setup-ruby@v1
         with:

.github/workflows/pre-release-tests.yml

@@ -21,7 +21,7 @@ jobs:
       RAILS_VERSION: ${{ matrix.rails-version }}
     name: integration-tests-against-rc (Rails ${{ matrix.rails-version }})
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:

.github/workflows/tests.yml

@@ -24,7 +24,7 @@ jobs:
       RAILS_VERSION: ${{ matrix.rails-version }}
     name: integration-tests (Rails ${{ matrix.rails-version }} with Ruby ${{ matrix.ruby-version }})
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -43,7 +43,7 @@ jobs:
     name: linter-check
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         env:
@@ -58,7 +58,7 @@ jobs:
     name: Yaml linting check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Yaml lint check
         uses: ibiqlik/action-yamllint@v3
         with:
@@ -68,7 +68,7 @@ jobs:
     name: smoke-test
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         env: