chore(automate): Update package.json to 2.5.11

Commit by [GitHub Actions](https://github.com/Cysharp/UniTask/actions/runs/26083685280)

Author: github-actions[bot]

src/UniTask/Assets/Plugins/UniTask/package.json

@@ -2,7 +2,7 @@
     "name": "com.cysharp.unitask",
     "displayName": "UniTask",
     "author": { "name": "Cysharp, Inc.", "url": "https://cysharp.co.jp/en/" },
-    "version": "2.5.10",
+    "version": "2.5.11",
     "unity": "2018.4",
     "description": "Provides an efficient async/await integration to Unity.",
     "keywords": [ "async/await", "async", "Task", "UniTask" ],