fix(deps): update dependency koa to v3.1.0

Author: renovate[bot]

examples/koa/package.json

@@ -9,7 +9,7 @@
   "dependencies": {
     "@types/koa": "3.0.1",
     "graphql-yoga": "workspace:*",
-    "koa": "3.0.3",
+    "koa": "3.1.0",
     "supertest": "7.1.4"
   },
   "devDependencies": {

package.json

@@ -111,7 +111,7 @@
       "esbuild": "0.25.11",
       "cookie": "1.0.2",
       "graphql": "16.11.0",
-      "koa": "3.0.3",
+      "koa": "3.1.0",
       "@changesets/assemble-release-plan": "5.2.3",
       "@types/react": "19.2.2",
       "multer": "2.0.2",