Bump actions/checkout from 3 to 4 (#705)

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...3df4ab1)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/ruby-core.yml

@@ -28,7 +28,7 @@ jobs:
           bundler: none
       - name: Save latest buildable revision to environment
         run: echo "REF=$(ruby -v | cut -d')' -f1 | cut -d' ' -f5)" >> $GITHUB_ENV
-      - uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v3.1.0
         with:
           repository: ruby/ruby
           path: ruby/ruby
@@ -47,7 +47,7 @@ jobs:
           ./configure -C --disable-install-doc
           make -j2
         working-directory: ruby/ruby
-      - uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v3.1.0
         with:
           path: ruby/irb
       - name: Sync tools

.github/workflows/test.yml

@@ -28,7 +28,7 @@ jobs:
       WITH_LATEST_RELINE: ${{matrix.with_latest_reline}}
     timeout-minutes: 30
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -55,7 +55,7 @@ jobs:
       WITH_LATEST_RELINE: ${{matrix.with_latest_reline}}
     timeout-minutes: 30
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with: