Bump actions/checkout from 2 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...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/codeql-analysis.yml

@@ -25,7 +25,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v2

.github/workflows/rubocop.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1

.github/workflows/test.yml

@@ -31,7 +31,7 @@ jobs:
       RAILS_VERSION: ${{ matrix.rails == '' && '6.1.6' || matrix.rails }}
       COVERAGE: ${{ matrix.coverage || '' }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: bundle install
         run: bundle install -j$(nproc) --retry 3
       - name: install simplecov-fork only for minitest with coverage