feat(deps): bump min node version to 14.x (#1034)

Node 12 has reached end of life so it is no longer being actively supported. constructs@10.x now requires node version >= 14.x

Author: kaizencc

.github/workflows/build.yml

@@ -54,8 +54,7 @@ const project = new cdk.JsiiProject({
   },
 
   stability: 'stable',
-  minNodeVersion: '12.7.0',
-  workflowNodeVersion: '12.22.0',
+  minNodeVersion: '14.17.0',
 
   compat: true,