Upgrade checkout task for linux-test

feature/init-positional-with-argument-rep

Author: roanutil

.github/workflows/ci.yml

@@ -49,6 +49,6 @@ jobs:
     environment: default
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Run Tests
         run: swift test --parallel