Update main.yml（change node version）

.github/workflows/main.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Setup node
       uses: actions/setup-node@v2
       with:
-        node-version: '12.14.0'
+        node-version: '14.21.3'
 
     - name: Build Root Project
       run: |