add bun runtime

## Why you need it?
A runtime that uses bun could make it easier to deploy actions written in TypeScript and provide better performance compared to the corresponding runtimes based on Node.js

## How it could be?
Nothing more than the similar runtimes like nodejs-based I guess

未指定文件、测试或入口点。首先定位现有的基于 Node.js 的运行时以及 TypeScript actions 的部署路径，然后将它们的运行时要求与 Bun 进行比较；当基于 Bun 的运行时能够部署并执行这些 actions，且行为与现有运行时相当时，即视为完成。

由索引模型根据 Issue 内容生成。