Update ssdk node deps to node 14

This updates the node dependencies for the ssdk libs to node 14, which
is the most recent version supported by Lambda.

Author: JordonPhillips

smithy-typescript-ssdk-libs/server-apigateway/package.json

@@ -29,13 +29,13 @@
   },
   "devDependencies": {
     "@types/jest": "^26.0.4",
-    "@types/node": "^12.7.5",
+    "@types/node": "^14.14.37",
     "downlevel-dts": "^0.7.0",
     "jest": "^26.1.0",
     "typescript": "~4.1.2"
   },
   "engines": {
-    "node": ">= 10.0.0"
+    "node": ">= 14.0.0"
   },
   "typesVersions": {
     "<4.0": {

smithy-typescript-ssdk-libs/server-common/package.json

@@ -29,14 +29,14 @@
   },
   "devDependencies": {
     "@types/jest": "^26.0.20",
-    "@types/node": "^12.7.5",
+    "@types/node": "^14.14.37",
     "downlevel-dts": "^0.7.0",
     "jest": "^26.6.3",
     "ts-jest": "^26.5.2",
     "typescript": "^4.2.2"
   },
   "engines": {
-    "node": ">= 10.0.0"
+    "node": ">= 14.0.0"
   },
   "typesVersions": {
     "<4.0": {