Update to latest checkout action to hide warnings

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
     container: devkitpro/devkitarm
     steps:
       - name: Checkout branch
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - uses: ./actions/setup
         with:
@@ -51,7 +51,7 @@ jobs:
         - '/tmp:/tmp'
     steps:
       - name: Checkout branch
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - uses: ./setup
         with: