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

No files, tests, or entry points are named. Start by locating the existing Node.js-based runtimes and the deployment path for TypeScript actions, then compare their runtime requirements with Bun; done means a Bun-based runtime can deploy and execute those actions with behavior comparable to the existing runtimes.

Written by the indexing model from the issue text.