Bump shell-quote from 1.7.3 to 1.8.4 in /react-express-mysql/frontend

Bumps [shell-quote](https://github.com/ljharb/shell-quote) from 1.7.3 to 1.8.4.
- [Changelog](https://github.com/ljharb/shell-quote/blob/main/CHANGELOG.md)
- [Commits](https://github.com/ljharb/shell-quote/compare/v1.7.3...v1.8.4)

---
updated-dependencies:
- dependency-name: shell-quote
  dependency-version: 1.8.4
  dependency-type: indirect
...

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