use node 14

.github/workflows/build.yml

@@ -9,20 +9,20 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x]
+        node-version: [14.x]
 
     steps:
     - uses: actions/checkout@v1
       with:
         submodules: true
-    - name: Use Node.js 18.x
+    - name: Use Node.js 14.x
       uses: actions/setup-node@v1
       with:
-        node-version: 18.x
+        node-version: 14.x
     - name: npm install, build, and test
       run: |
-        yarn add gatsby --global
-        yarn --frozen-lockfile
-        yarn run build:prod
+        npm i -g gatsby
+        npm ci
+        npm run build:prod
       env:
         CI: true