fix(deps): update dependency mongoose to v6 [security]

Author: renovate[bot]

package.json

@@ -18,7 +18,7 @@
     "graphql-tools": "6.0.1",
     "jsonwebtoken": "8.5.1",
     "lodash.keyby": "4.6.0",
-    "mongoose": "5.9.15",
+    "mongoose": "6.13.6",
     "validator": "13.0.0"
   },
   "devDependencies": {