chore(package.json): bump engines to node >= 14.0.0 (smithy-lang#623)

Author: trivikr

smithy-typescript-codegen/src/main/resources/software/amazon/smithy/typescript/codegen/base-package.json

@@ -34,7 +34,7 @@
     }
   },
   "engines": {
-    "node": ">=12.0.0"
+    "node": ">=14.0.0"
   },
   "typesVersions": {
     "<4.0": {