chore(deps): update dependency @types/sequelize to v4.28.6

Author: renovate-bot

sample/07-sequelize/package-lock.json

@@ -31,7 +31,7 @@
     "typescript": "3.6.4"
   },
   "devDependencies": {
-    "@types/sequelize": "4.28.5",
+    "@types/sequelize": "4.28.6",
     "@nestjs/cli": "6.10.4",
     "@nestjs/schematics": "6.7.0",
     "@nestjs/testing": "6.8.3",