fix(deps): update dependency koa to v3.1.1

Author: renovate[bot]

package.json

@@ -22,7 +22,7 @@
     "debug": "4.4.3",
     "episode-parser": "2.0.2",
     "helmet": "^8.0.0",
-    "koa": "3.0.3",
+    "koa": "3.1.1",
     "koa-bodyparser": "4.4.1",
     "koa-helmet": "8.0.1",
     "koa-qs": "3.0.0",
@@ -37,7 +37,7 @@
   },
   "devDependencies": {
     "@types/jest": "^30.0.0",
-    "@types/koa": "2.15.0",
+    "@types/koa": "3.0.1",
     "@types/koa-bodyparser": "4.3.13",
     "@types/koa-helmet": "6.1.0",
     "@types/koa-router": "7.4.9",