bump ts version (#350)

Author: Mengqi Yu

ts/demo-functions/package-lock.json

@@ -41,7 +41,7 @@
     "tslint": "^6.1.3",
     "tslint-config-prettier": "1.18.0",
     "tslint-consistent-codestyle": "^1.16.0",
-    "typescript": "~3.9.9"
+    "typescript": "^4.3.2"
   },
   "kpt": {
     "docker_repo_base": "gcr.io/kpt-functions"

ts/demo-functions/package.json

@@ -23,7 +23,7 @@
     "create-kpt-functions": "^0.17.0",
     "jasmine": "^3.7.0",
     "tslint": "^6.1.3",
-    "typescript": "^3.9.9"
+    "typescript": "^4.3.2"
   },
   "kpt": {
     "docker_repo_base": "gcr.io/kpt-functions"