Bump actions version.

Author: rogerluan

.github/workflows/run-tests.yml

@@ -14,7 +14,7 @@ jobs:
         ruby: ['2.7', '3.0', '3.1', '3.2', '3.3', '3.4']
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}