fix(deps): update dependency koa to v2.15.4 [security]

Author: renovate[bot]

apps/strapi-node/src/package.json

@@ -13,7 +13,7 @@
   },
   "dependencies": {
     "knex": "0.21.17",
-    "koa": "2.13.1",
+    "koa": "2.15.4",
     "module-alias": "2.2.2",
     "sqlite3": "latest",
     "strapi": "3.4.5",