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.

Inspect microbundle's dependency declaration for rollup-plugin-terser and the resulting serialize-javascript dependency chain. Try the proposed @rollup/plugin-terser replacement, run the existing build or test commands, and confirm that the vulnerability is gone without introducing regressions.

索引モデルが issue の本文から書いたものです。