chore(infra): set minimum node version to 15

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x]
+        node-version: [15.x]
 
     steps:
       - uses: actions/checkout@v2

package-lock.json

@@ -41,6 +41,9 @@
         "typescript": "^4.3.5",
         "webpack": "^5.44.0",
         "webpack-cli": "^4.7.2"
+      },
+      "engines": {
+        "node": ">=15"
       }
     },
     "node_modules/@babel/code-frame": {

package.json

@@ -73,5 +73,8 @@
     "form-data": "^4.0.0",
     "https": "^1.0.0",
     "tough-cookie": "^4.0.0"
+  },
+  "engines": {
+    "node": ">=15"
   }
 }