Update to latest checkout GH actions package

This resolves some deprecations checkout being run on a
deprecated node version

.github/workflows/test.yml

@@ -1,6 +1,6 @@
 name: Test
 
-concurrency: 
+concurrency:
   group: ${{ github.ref }}
   cancel-in-progress: true
 
@@ -22,15 +22,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: 
+        ruby-version:
           - '2.7'
           - '3.0'
           - '3.1'
           - '3.2'
           - '3.3'
 
     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):