chore(deps): update dependency typescript to v3.9.6

Author: renovate-bot

package.json

@@ -45,7 +45,7 @@
     "tslint-config-prettier": "1.18.0",
     "tslint-plugin-prettier": "2.3.0",
     "vuepress": "1.5.0",
-    "typescript": "3.9.3"
+    "typescript": "3.9.6"
   },
   "repository": {
     "type": "git",