Update github_pages.yml (#171)

.github/workflows/github_pages.yml

@@ -9,14 +9,14 @@ on:
 
 jobs:
   deploy:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Setup Node
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v4
         with:
-          node-version: '12.x'
+          node-version: '14.x'
 
       - name: Cache dependencies
         uses: actions/cache@v1