Security vulnerability via transitive dependency on `serialize-javascript` via `rollup-plugin-terser`

I've started to see vulnerability reports on a number of projects that all look like this: https://github.com/bullet-train-co/bullet_train-core/security/dependabot/557

The issue arises because `microbundle` depends on the deprecated `rollup-plugin-terser` package which has its dependency on `serialize-javascript` declared with `^4.0.0`.

Updating `microbundle` to `@rollup/plugin-terser` should fix the dependency chain, but I don't know if it would introduce other issues.

檢查 microbundle 中對 rollup-plugin-terser 的相依性宣告，以及由此產生的 serialize-javascript 相依性鏈。嘗試使用建議的 @rollup/plugin-terser 進行替換，執行現有的 build 或 test 指令，並確認漏洞已消除且未引入回歸問題。

由索引模型根據 Issue 內容生成。