Bump browserslist from 4.20.0 to 4.28.8 in /react-nginx

Bumps [browserslist](https://github.com/browserslist/browserslist) from 4.20.0 to 4.28.8.
- [Release notes](https://github.com/browserslist/browserslist/releases)
- [Changelog](https://github.com/browserslist/browserslist/blob/main/CHANGELOG.md)
- [Commits](https://github.com/browserslist/browserslist/compare/4.20.0...4.28.8)

---
updated-dependencies:
- dependency-name: browserslist
  dependency-version: 4.28.8
  dependency-type: indirect
...

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