build(deps): bump form-data from 3.0.1 to 3.0.4 in /src/handler/webui

Bumps [form-data](https://github.com/form-data/form-data) from 3.0.1 to 3.0.4.
- [Release notes](https://github.com/form-data/form-data/releases)
- [Changelog](https://github.com/form-data/form-data/blob/v3.0.4/CHANGELOG.md)
- [Commits](form-data/form-data@v3.0.1...v3.0.4)

---
updated-dependencies:
- dependency-name: form-data
  dependency-version: 3.0.4
  dependency-type: indirect
...

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

Author: dependabot[bot]