Update update-usaco.yml

Author: ryanchou-dev

.github/workflows/update-usaco.yml

@@ -7,15 +7,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout usaco-guide
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - name: Use Node.js 20.x
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v4
         with:
           node-version: 20.x
       - name: Checkout usaco-problems
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           repository: ${{ github.repository_owner }}/usaco-problems
           path: usaco-problems