Bump actions/checkout from 3 to 4 (ruby#1014)

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

.github/workflows/protocol.yml

@@ -24,7 +24,7 @@ jobs:
         ruby-version: ['2.6', '2.7', '3.0', '3.1', 'head', 'debug']
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Ruby
     # To automatically get bug fixes and new Ruby versions for ruby/setup-ruby,
     # change this to (see https://github.com/ruby/setup-ruby#versioning):

.github/workflows/ruby-macos.yaml

@@ -24,7 +24,7 @@ jobs:
         ruby-version: ['3.2', 'head']
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Ruby
     # To automatically get bug fixes and new Ruby versions for ruby/setup-ruby,
     # change this to (see https://github.com/ruby/setup-ruby#versioning):

.github/workflows/ruby.yml

@@ -24,7 +24,7 @@ jobs:
         ruby-version: ['2.6', '2.7', '3.0', '3.1', '3.2', 'head', 'debug']
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Ruby
     # To automatically get bug fixes and new Ruby versions for ruby/setup-ruby,
     # change this to (see https://github.com/ruby/setup-ruby#versioning):

.github/workflows/test_test.yml

@@ -24,7 +24,7 @@ jobs:
         ruby-version: ['3.0', '3.1', '3.2', 'head', 'debug']
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Ruby
     # To automatically get bug fixes and new Ruby versions for ruby/setup-ruby,
     # change this to (see https://github.com/ruby/setup-ruby#versioning):