Bump rollup from 4.18.0 to 4.20.0 in /js

Bumps [rollup](https://github.com/rollup/rollup) from 4.18.0 to 4.20.0.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v4.18.0...v4.20.0)

---
updated-dependencies:
- dependency-name: rollup
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>