fix: change workflow to release under 14.x instead of 12.x (#472)

Author: brettstack

.github/workflows/release-on-push-to-mainline.yml

@@ -33,8 +33,8 @@ jobs:
       run: npm run lint
 
     - name: Release
-      if: github.event_name == 'push' && github.ref == 'refs/heads/mainline' && matrix.node-version == '12.x'
+      if: github.event_name == 'push' && github.ref == 'refs/heads/mainline' && matrix.node-version == '14.x'
       run: npm run release
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        NPM_TOKEN: ${{ secrets.NPM_TOKEN }} 
+        NPM_TOKEN: ${{ secrets.NPM_TOKEN }}